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Today's Top Web Questions+-
Why do those red Alert banners get posted?

Alert banners are posted on by government agencies, particularly when weather or other events are expected or occurring that could pose a threat to public safety, such as poor visibility, dangerous driving conditions and more. In some cases the alert is considered high priority, and appears in full on the page immediately. This is to ensure that website users are aware of the event. Once the alert page is closed, it will not appear automatically unless the alert is updated.

How do I change to °F or °C?

You can change to Fahrenheit or to Celsius on the desktop site either by clicking directly on the temperature next to the weather icon on the forecast page, or by clicking on the °C or °F at the very top of the page, in the grey bar.

On the mobile website please find these settings by clicking on the "hamburger menu" icon, and scrolling to the bottom of the menu.

What does the ∼ mean? (Example: ∼5 mm of rain)
The ~ (also known as a tilde) is a mathematical symbol that indicates "approximately".
Have a questions about our products, or perhaps how we forecast? Chances are, we've got the answer in the list below. If we don't, please feel free to contact us.
Web navigation and basic FAQs+-
How do I find my city forecast?
There are several ways to locate your favourite city. You can use the search box and type in the city name, or you can also locate your cities on the home page map by panning and zooming the map and clicking on the weather icons to take you there.
How do I get weather details like wind, barometric pressure, humidity, ceiling etc.?
As a weather expert, you like to see lots of information! Well, we’ve got it. Once you’re on your city forecast page and looking at the current weather, look just below the current observations. Additional details that are available for this location will be included here.
How do I see expected night time conditions in my long term forecast?
You can view the night time temperatures and conditions by clicking on the night link in the upper right corner of the 7 Days tab.
Where is hourly, 36 hours and 14 Day trend?
To help you better plan your day, we’ve put all the weather information right at the top of your forecast page. Simply tab through each forecast period to view the time and days you were looking for.
How do I change to Fahrenheit?
You can easily switch to Fahrenheit or Celsius by clicking on the “F” or "C" at the extreme top of any page, located to the right.
How do I use the new maps?
There are a few different ways. On the homepage you can put your cursor on top of a weather flag, which will provide more in-depth coverage on that area. When clicking on the flag, you’ll be brought to a forecast page with weather information specific to that location.
On the forecast pages, you’ll find the satellite and radar map just below the forecast information. When clicking on the chevrons pointing downwards, the map will expand and show you the recent information and forecast radar for that location.
You can also see recent satellite, forecast and radar information, traffic flow maps for major roads and highways, as well as the current high level weather information for neighbouring cities and towns: these are accessible from the dropdown in the map module on the forecast pages, from the individual map pages, and from the navigation.
Can I set my favourite locations?

Absolutely! To get started, you can either use search to find your location, or select one from the interactive map on the homepage.
Once you are on a location page that you wish to save as a favourite, simply click on the + icon next to the location name.

You can also add a location to your favourites by clicking on the + icon at the far right side of the navigation; this will open a search overlay into which you can enter a location name or, for a more precise PointCast location, a Canadian postal code or U.S. ZIP code. Select the correct location from the resulting dropdown, click "save" and it will be added to your favourites.

Edit or add to your favourites anytime: simply click on the "settings" icon at the very top of the page to go to your profile, and select the "Edit Locations" tab. In this section you can add, remove and edit your saved locations.

What do the ↓ and ↑ arrows indicate?
These arrows indicate that this particular area can be collapsed or expanded to fit your needs. Once you organize the site using these arrows, those settings will be saved for your next visit, or until you delete your cookies.
Can I reorganize the content? (What does the ☩ mean?)
Yes! To ensure the site fits the needs of your lifestyle, you can drag and drop the maps, news, gallery, or insider insights sections. In order to do so, click on the arrows and drag them on top or below other sections. You can keep doing this until the sections are organized to your liking.
Can I customize the site?
Yes, and that's what makes us so excited about it! Once you've saved locations, organized the sections and selected your favourite maps, is ready to provide you with the reliable and accurate weather information in the way that you want it.
I like the weather images in the background. How do they work?
The background images of the site will change frequently to reflect the current weather conditions. If it's sunny, we'll display sunny skies. If it's rainy, you’ll have little droplets on your screen.
What happens when there's a weather alert?
We've done everything we can to keep you in the know. When a location is under a weather alert or a public alert, a red banner appears at the top of the location's page which links to an alert page containing all of the relevant information to the alert: alert details, live cameras, topical news stories, as well as storm tracking capabilities right from your desktop. If an alert is in effect for one of your saved locations, an icon appears in that location on your favourites bar.
When an alert is serious enough that we really need to make sure everyone knows about it, the alert page will be displayed automatically when you first go to that location's forecast page. You can still see the forecast page by clicking on “Close Alert Page” in the yellow banner.
Something odd happened on the site.
We're working through a few things and would love your feedback. To report something please contact us and describe your experience, so we can troubleshoot to the best of our ability.
I want to share my opinion!
And we want to hear it! Please share your opinion and tell us your thoughts.
I need to make an account.
Sounds good! Start by creating an account and you’ll be ready in just a few minutes to comment and upload photos and videos.
I’m having trouble logging in to my account.
Not a problem. You can use the password reminder page. If you are having another kind of issue with accessing your account, please contact us.
Weather icons+-
What do the weather icons mean?

u Light snow.

fn Mainly cloudy with a few clear breaks.

f Mainly cloudy with a few sunny breaks.

en A few clouds.

e A mix of sun and clouds.

cn Mainly clear.

b Mainly sunny.

an Clear.

a Sunny.

m Rain will fall heavy at times.

Moderate Rain Moderate rain is likely.

Light rain/Light showers Light rain may fall steadily, or as light showers.

Cloudy with Heavy Rain Cloudy periods with heavy rain showers.

Sun and Clouds with Chance of Rain A mix of sun and clouds with a chance of rain showers.

Few Clouds Slight Rain A few clouds with a slight chance of a light rain shower.

Mainly Sunny Chance of Light Rain Mainly sunny with a slight chance of a light rain shower.

Cloudy with Drizzle Mainly cloudy with drizzle.

Mist or Fog Areas of mist or fog.

Mainly Cloudy Light Snow Mainly cloudy with light snow.

Mainly Cloudy Snow Mainly cloudy with snow.

q Mainly cloudy with freezing rain.

p Mainly cloudy with a mix of snow and rain is possible.

k Cloudy skies.

jn Cloudy periods with a chance of snowfall.

j A mixture of sun and clouds with a chance of snowfall.

Blowing Snow Blowing snow.

hn Cloudy periods with a mix of rain and snow possible.

h A mix of sun and clouds with a mix of rain and snow possible.

gn Cloudy periods with a chance of rain and risk of a thunderstorm.

g A mix of sun and clouds with a chance of rain and risk of a thunderstorm.

Cloudy chance of rain and thunder Cloudy skies with the chance of rain and risk of a thunderstorm.

1. Appropriate Comments
We’re trying to make more dynamic than ever, and always love user participation. Several sections of the site welcome user comments, but we do need to keep some things in mind to ensure comments entertain, inform, question and motivate.
Please remember:
• Comments should stay focused on the subject. Off-topic postings may be deleted.
• Be polite.
• Avoid making negative comments about or toward a specific person.
• You may provide links to other areas of As for external web addresses, we allow one per post, as text only, not as a hyperlink.
• One account per participant, please.
Please do not post:
• Lengthy quotes or excerpts - we want to hear your own opinion.
• Press releases and/or advertising.
• Personal contact information, including e-mail addresses, phone numbers and street addresses.
• Duplicate or repetitive comments.
• Argumentative remarks. Our commenting platform should be welcoming to all participants.
• Racist, sexist or otherwise offensive language.
• Personal attacks and defamatory statements.
• Copyright infringement (copying from other sources and websites without permission and attribution).
• Violations of someone’s privacy.
• Threats or the suggestion of committing a criminal act.
• Insensitive comments regarding the death or injury of people or animals.
• Messages in all CAPS (this makes it difficult to read and is commonly seen as yelling in a digital format).
Violating the above guidelines will result in the removal of your comment, and possibly the banning of your account.
2. How do I comment?
In order to comment, you have to login with either you Weather Network account, or your Facebook account – whichever you prefer.
3. Can I include personal information in comments?
Your display name, which links to your profile, will appear with your comment, and we may use your real name and city from your profile if we use your submission in our news coverage. However, contact information should not be part of your postings. In order to maintain your privacy, please do not share e-mail addresses, phone numbers or mailing addresses.
4. How are comments moderated?
Comments are activated automatically and are reviewed after being posted. Inappropriate words included in comments will be automatically replaced before the comment is posted.
Any comment may be removed if our guidelines are not followed. Please note that The Weather Network may decide to remove a comment that is deemed inappropriate – for any reason, at any time.
5. What if I see a comment I don’t like?
If you disagree with a posting, that is your opportunity to respond with your own comment. If you feel a comment has violated any of our guidelines, click on the "Report abuse" link found at the bottom of the comment, and we will investigate.
For more information, visit our Terms of Use page. These guidelines may be updated at any time.
Photos and Videos+-
1. How do I contribute a photo or video?
To contribute your own image, visit our Photos & Videos page and click on the orange "Upload" button near the top. On the "Login or Create an Account" page, enter your Email/Login and Password. If you have not contributed a photo or video before, you will need to create an account. Fill in the required fields and click "Create Your Account". After successfully logging in, fill in the form fields to describe your photo or video. Be sure to check the file format with the list of supported formats on the right side of this page. Click "Upload Now!".
2. How do I edit or delete photos from my account?
Once a photo or video has been uploaded, it unfortunately cannot be edited or deleted by the user. If you want one of your photos or videos removed from our system, use the Contact Us page to make a request. Please provide your Email/Login, the name of the photo or video and the date it was uploaded.
3. How do I report a spelling or grammar error?
While we take time to edit and proof our news stories, our writers do not edit the photos or videos submitted to the Photos & Videos section for spelling or grammar mistakes.
4. I can’t find my uploaded photos or videos. Is something wrong?
Uploaded photos and videos can take up to 24 hours to be reviewed and approved by our moderators. After 24 hours, try uploading the photos or videos again. If they do not display in the "My Uploads" section, please let us know using the Contact Us form.
5. Can I add comments to photos or videos?
Absolutely! We love it when our users comment on photos and videos. If you have an account with or have a Facebook account, click "Log in" located below the photo or video’s description.
If you wish to sign in with Facebook, click on the “Sign in with Facebook” button located on the left. If you wish to sign in with your account, fill in your e-mail and password on the right and click the “Login” button below.
If you do not have a or Facebook account, click “Sign up” below the photo or video’s description and fill out the required fields.
1. What is the "Follow me" functionality?
The application makes use of the GPS coordinates and shows you the weather for where you happen to be, without needing to select the location, state etc. The feature is called the 'Follow me' functionality. You can enable or disable "Follow me" from the Locations screen which is accessible by tapping the "i" in the right corner beside the location name. Want to learn more about the iPhone app? Watch our video tutorial.
2. What is PointCast?
PointCast technology delivers hyper local forecasts and weather information with precision and accuracy beyond compare. By providing your POSTAL code, ZIP code or by activating Follow me we can deliver a hyper local PointCast as close as 1km/0.6miles using your latitude and longitude. More PointCast information.
3. Why does my follow me city have the pin symbol?
The PointCast pin indicates the most local forecast is being provided. By enabling Follow me, we receive your latitude and longitude information and automatically deliver PointCast, a hyper local forecast and weather information as close as 1km/0.6miles. More PointCast information.
1. I can't find more detailed current observation information, where is it?

To see detailed current observation data, tap the top portion of the screen near the sky conditions icon. The current observations screen will expand displaying wind speed & direction, humidity, pressure, visibility, ceiling, sunrise/sunset times, and yesterday's high/low temperatures.

The iPhone app is highly interactive so tapping weather data will often provide more detailed information. For city, golf, ski and airport locations, air quality, UV report and pollen data is displayed, for more information simply tap the report to see more details.

For school locations, school day forecast for to and from school is displayed and for park locations, bug report is displayed. To get more detailed bug information, tap the bug report. Tap the icon area again to return to the previous view. Want to learn more about the iPhone app? Watch our video tutorial.

2. How do I add a City, Park, School or Airport?

To add a location tap the "i" icon in the right corner of the screen beside the location name. The Location screen will open, you can add a location by tapping the "+" sign in the top left corner or by tapping the PointCast button in the bottom right corner of the screen.

If you tap the "+" sign, the search screen will open with a list of nearby locations. You can choose from these or search for a location using the search box. You can add a PointCast location by entering your Postal Code or US ZIP code, or search for cities, parks, schools, and airports by name. Tap the location you want to save. Postal codes can be entered with or without spaces and are not case sensitive. For example, you can enter K1A 0A9 or K1A0A9 or K1a 0a9 or k1a0A9, all combinations will give you Ottawa, ON, Canada K1A 0A9. ZIP codes must not include spaces.

Tap the "close" button in the top left corner to exit the Locations page and return to the forecast page. Want to learn more about the iPhone app? Watch our video tutorial.

3. What are the other features on this app?

All the cool features can be found on the dashboard which is accessible from every page by tapping the menu button Menu Button in the top left corner. From the dashboard you can access all content available in the application including: 14 day trends, Charts, Bug reports (with Parks), Pollen, Golf, and Ski to name a few. Want to learn more about the iPhone app? Watch our video tutorial.

4. What do the red and yellow alerts mean on the home screen?

As on TV and the Web, the red and yellow banners refer to severe or active weather. In the iPhone app, the most severe alert displays in the banner. Tapping on the banner will take you to the Alerts page which lists all current warnings and alerts. You can also tap on the warning or alert to get more details or on the "View alerts" button. If you are witnessing severe or active weather and want to submit a photo or video simply tap the "Snap a pic" button. To see the latest weather videos tap the "Watch live" video.

5. How do I see more short term weather information?

To see detailed weather data for the short term periods, tap on the period (i.e., Afternoon). The details page will open displaying wind speed & direction, humidity, P.O.P., rain and snow amounts as well as the hourly forecast for that period. You can tap the other short term periods (i.e., Evening) to see the hourly forecast for that period. This application is highly interactive, by tapping the individual hours, the data for that time will display above. To return to the forecast page, tap the "x" in the top right corner to close the page. Want to learn more about the iPhone app? Watch our video tutorial.

6. How do I find long term weather information?

The long term weather information now includes the next fourteen days. To see the long term data, on the forecast page swipe upward from the short term weather information.

To see more detailed long term data, tap the day you want to see. The details page will open displaying wind speed & direction, daylight hours, P.O.P., rain and snow amounts as well as the 14 Day Trend graph. You can move the 14 Day Trend graph back and forth to see all the days.

This version of The Weather Network application is more interactive, tap a specific day and the data will display above. To return to the forecast page tap the "x" in the top right corner.

Want to learn more about the iPhone app? Watch our video tutorial.

7. Where can I find the hourly forecast?
The hourly forecast is available on the Short Term details page for a short term period (i.e., Afternoon) to open the details page. This application is more interactive, by tapping the individual hours, the data for that time will display above. You can also access it from the dashboard by tapping Charts. The dashboard can be accessed from any page by tapping the icon in the top left corner. Want to learn more about the iPhone app? Watch our video tutorial.
8. How do I get the 14 Day Trend?
The 14 Day Trend is accessible from the long range forecast. Tap any day in the long range forecast and the details page will open. The 14 Day Trend graph is displayed at the bottom of the page. Improved interactivity allows you to move the graph back and forth through the 14 days and tapping an individual day will cause that day's forecast to display above. The 14 Day Trend is also accessible from the dashboard, the icon in the top left corner of every page.
9. Where do I find the satellite and radar maps?
Satellite and Radar maps are accessible from the dashboard, the icon in the top left corner of every page. Tap the Maps icon. Want to learn more about the iPhone app? Watch our video tutorial.
10. Can I get weather news and videos?
News stories and videos are accessible on the dashboard under News. As well, active weather and local forecasts are accessible from the dashboard under Video. Want to learn more about the iPhone app? Watch our video tutorial.
11. How do I remove a location?
To remove a location tap the "i" icon in the right corner of the screen beside the location name. The Location page will open listing all of your saved locations. Tap the "edit" button in the bottom right corner of the screen. The screen will change to "Edit" mode with a delete icon beside each location. Tap the location you wish to remove; a "delete" button will display. Tap the "delete" button and the location will be removed from the list. Tap the "done" button in the bottom right corner to exit the "Edit" mode and then tap the "close" button in the top right corner to return to the forecast page. Want to learn more about the iPhone app? Watch our video tutorial.
12. I can't delete a city unless I add another city first. Why?
The Weather Network app logic requires two locations be saved to the Locations List before one location can be deleted in order to ensure there is always a location being displayed. This logic applies regardless of whether "Follow Me" is enabled or not. Want to learn more about the iPhone app? Watch our video tutorial.
13. How do I report a problem or make a comment?
We are happy to hear from our users especially if they are experiencing technical difficulties. Please copy and paste the following email address and send us an email outlining the problem or comment. Please include which iPhone you are using.
Android Phone FAQs+-
1. Why does my follow me city have the pin symbol?
The PointCast pin indicates the most local forecast is being provided. By enabling ‘Follow Me,’ we receive your latitude and longitude information and automatically deliver PointCast, a hyper local forecast and weather information as close as 1km/0.6miles.
2. The app is now called "The Weather Network application" instead of WeatherEye, why?
We have proudly renamed our applications "The Weather Network" so that it now shares its name with our other services available on TV and web that you are familiar with. It will also help with finding the application in the Android Market.
3. Why is my "Follow Me" location sometimes a location several kilometres away?
The "Follow Me" function looks for the closest weather station to your current location based on distance which may not be the weather station in your city. For example, if you live in a large city the weather for that city may come from the local airport often located outside the city centre. As a result, depending on where you are located in relation to the airport, the closest weather station to may actually be in the neighbouring town.
4. I can’t find more detailed current observation information, where is it?

To see detailed current observation data, tap the top portion of the screen near the sky conditions icon. The current observations screen will expand displaying wind speed & direction, humidity, pressure, visibility, ceiling, sunrise/sunset times, and yesterday’s high/low temperatures.

The new app is highly interactive so tapping weather data will often provide more detailed information. For city and airport locations, air quality, UV report and pollen data is displayed, for more information simply tap the report to see more details.

For school locations, school day forecast for to and from school is displayed and for park locations, bug report is displayed. To get more detailed bug information, tap the bug report. Tap the icon area again to return to the previous view.

5. How do I add a City, Park, School or Airport location?

To add a location tap the "i" icon in the right corner of the screen beside the location name. The Location screen will open, you can add a location by tapping the "+" sign in the top right corner or by tapping the PointCast button in the bottom right corner of the screen.

If you tap the "+" sign, the search screen will open with a list of nearby locations. You can choose from these or search for a location using the search box. You can add a PointCast location by entering your Postal Code or US ZIP code, or search for cities, parks, schools, and airports by name. Tap the location you want to save. Postal codes can be entered with or without spaces and are case sensitive. For example, you can enter K1A 0A9 or K1A0A9 or K1a 0a9 or k1a0A9, all combinations will give you Ottawa, ON, Canada K1A 0A9. ZIP codes must not include spaces.

Tap the "close" button in the top left corner to exit the Locations page and return to the forecast page.

6. How do I move between saved locations?

From the main weather page you can move between locations by swiping from left to right or right to left. By tapping the "i" icon in the bottom corner, you can access the Locations page where tapping a city will take you to its main weather page.

7. What are the new features on this app?

All the cool features can be found on the dashboard which is accessible from every page by tapping the menu button Menu Button in the top left corner. From the dashboard you can access all content available in the application including: 14 day trends, Charts, Bug reports (with Parks), and Pollen to name a few.

8. What do the red and yellow alerts mean on the home screen?

As on TV and the Web, the red and yellow banners refer to severe or active weather. In the new Android app, the most severe alert displays in the banner. Tapping on the banner will take you to the Alerts page which lists all current warnings and alerts. You can also tap on the warning or alert to get more details.

9. How do I see more short term weather information?

To see detailed weather data for the short term periods, tap on the period (i.e., Afternoon). The details page will open displaying wind speed & direction, humidity, P.O.P., rain and snow amounts as well as the hourly forecast for that period. You can tap the other short term periods (i.e., Evening) to see the hourly forecast for that period.

This new application is highly interactive, by tapping the individual hours, the data for that time will display above. To return to the forecast page, tap the “x” in the top right corner to close the page.

10. How do I find long term weather information?

The long term weather information now includes the next fourteen days. To see the long term data, on the forecast page swipe upward from the short term weather information.

To see more detailed long term data, tap the day you want to see. The details page will open displaying wind speed & direction, daylight hours, P.O.P., rain and snow amounts as well as the 14 Day Trend graph. You can move the 14 Day Trend graph back and forth to see all the days.

This new version of The Weather Network application is more interactive, tap a specific day and the data will display above. To return to the forecast page tap the “x” in the top right corner.

11. Where can I find the hourly forecast?

The hourly forecast is available on the Short Term details page – tap a short term period (i.e., Afternoon) to open the details page. This new application is more interactive, by tapping the individual hours, the data for that time will display above.

You can also access it from the dashboard by tapping Charts. The dashboard can be accessed from any page by tapping the icon in the top left corner.

12. How do I get the 14 Day Trend?

The 14 Day Trend is accessible from the long range forecast. Tap any day in the long range forecast and the details page will open. The 14 Day Trend graph is displayed at the bottom of the page. Improved interactivity allows you to move the graph back and forth through the 14 days and tapping an individual day will cause that day’s forecast to display above.

The 14 Day Trend is also accessible from the dashboard, the icon in the top left corner of every page.

13. Where do I find the satellite and radar maps?

Satellite and Radar maps are accessible from the dashboard, the icon in the top left corner of every page. Tap the Maps icon.

14. Can I get weather news and videos?

New to The Weather Network for Android application, you can now get weather news stories and videos accessible on the dashboard under News.

15. How do I remove a location?

To remove a location tap the "i" icon in the right corner of the screen beside the location name. The Locations page will open listing all of your saved locations. To remove a location, press the icon to the right of the location name you wish to delete and drag to the left. This will remove the location from the list.

16. How do I report a problem or make a comment?

We are happy to hear from our users especially if they are experiencing technical difficulties. Please contact us and be sure to include which Android you are using.

BlackBerry FAQs+-
1. How do I add a city?

From the main menu, click "Add City". From the Add City screen, you can either search for a PointCast location by entering a Postal Code or a US ZIP code or by entering a city location by name. You can also click "Add locations near you" to see a list of cities closest to you.

Postal codes can be entered with or without spaces and are case sensitive. For example, you can enter K1A 0A9 or K1A0A9 or K1a 0a9 or k1a0A9, all combinations will give you Ottawa, ON, Canada K1A 0A9. ZIP codes must not include spaces.

2. I don't see an icon on my Homescreen only a swirl, what does that mean?

The icon on the Homescreen displays the sky conditions for a location. Sky conditions come either from a person monitoring the conditions or from a machine. Not all weather stations offer sky conditions. The Follow Me function looks for the closest location to you which may not offer an icon.

3. Will the Homescreen icon and / or the Follow me function add to my roaming charges when I travel abroad?

Yes, like any application that updates automatically, the Homescreen icon and the Follow me will add to your roaming charges. Before you go abroad, disable the Homescreen icon by going into the Options screen from the main menu and turning it icon off. Also disable the Follow me function by unchecking the box on the main menu.

iPad FAQs+-
1. How do I add a location?

You add a location through the add location map. You can access the map through the Location List by tapping on the Location name in the yellow menu bar and selecting the + button. Also, you can access the map from the side bar menu that can be accessed from the top right of the yellow bar (insert icon here), and by tapping ‘+ Add a location’.

Once you are in the Add location map, you can manually search for a location by typing a location name or by entering a North American POSTAL/ZIP code in the search box at the top of the screen. This will reveal a list of locations that can be accessed at any time from the list button to the right of the search box. Tapping on the location name will save it and take you directly to the location’s Dashboard or tapping the pin icon will allow you to view it on the map.

If your location services are ON the map will automatically provide you nearby locations to choose from. Tap the map pin to pop-up the location name and options. Selecting the + button you will add the location to your saved list and continue exploring on the map, or you can tap the location name to save and go directly to the location Dashboard.

See #7 for a detailed explanation of the Add Location Map functionality.

2. How do I delete & re-order locations?

You can access the list of your saved locations by tapping on the location name in the yellow menu bar or in the Add Location Map by tapping on the saved locations icon (insert icon here). Swipe left to reveal the Delete button. Long press (press and hold) to drag and drop locations into a specific order.

3. How do I change from Metric to Imperial? Or from Celsius to Fahrenheit?

Open the side bar by tapping on the menu icon Menu Button. Tap on the settings cog wheel button at the bottom left of the Side Bar drawer. This will bring up the settings pop over where you can adjust the units of measurement for a specific location or apply your choice to all saved locations. Please note Ceiling data is only available in Feet and will not adjust when Metric settings selected.

4. What content is available to me and how does it work?

a. Add location map

You can access the Add Location map by clicking on the Location name in the yellow menu bar and selecting the + button or tap + Add a location in the side bar (insert icon here).

Once you are in the Add location map you can view saved locations (insert icon here), long press (press and hold) and drag and drop to re-order saved locations, swipe left to delete, click on the pin icon beside the name to focus the map around a specific location or tap the location name to exit to the Dashboard.

The Layer button (insert icon here) filters location types (Owned/Saved, Cities, Schools, Parks, Airports) to narrow down what is displayed on the map or within search results.

If location services are ON, tapping the GPS arrow will focus the map to locations nearby.

North American users will have a PointCast search. By providing your POSTAL code, ZIP code or by activating Follow me we can deliver a hyper local PointCast forecast as close as 1km/0.6miles using your latitude and longitude. All other locations can find a location by typing in the location name in the search box.

A manual search entry or having Location Services ON will populate a list of locations from the list button to the right of the search box. You can tab between available Cities, Airports, Schools and Parks that have been organized within this list view. Tapping on the location name saves the location and takes you directly to the Dashboard. Tapping on the pin icon will bring up the pin in the location map.

You can exit the Add Location map by tapping on the X button in the top left corner. In order to close the map and continue to a dashboard, you need to have at least one location saved or have Follow me turned on.

b. Dashboard

The dashboard is a collection of modules that provide an overview of all the content we offer for your specific location. Tapping on a module will navigate to a full detail view of the content selected. Please note the Dashboard content varies by location based on regional availability.

c. Sidebar

The side bar is a full list of the products available for that location. You can click on any item to navigate to the full detail view. At the bottom of the Side Bar you will find the app settings and a link to the app FAQ.

5. How do I stop the app from running in the background of my device?

To remove the app from multi-task simply double tap the home button on the iPad device. This will reveal all of the currently applications running. Swipe upwards to clear each item from running in the background. This will help to preserve the battery life and improve performance on your device overall.

Android tablet FAQs+-
1. How do I download The Weather Network App for Android Tablet?

You can download The Weather Network App for Android Tablet in Google Play or you can access Google Play directly from your Android Tablet by selecting the Google Play icon.

Tablet Menu Image

2. Do I need to provide my demographic information?

No, providing your demographic information is optional. By doing so you help us better understand our users allowing us to improve our products and services. This information is for internal purposes only and will not be shared. Click here to review our privacy policy. If you do not wish to share your demographic information you can opt out simply by selecting 'No thanks'.

3. Follow Me and other default settings

If you are installing our app for the first time or upgrading from an older version of our app, you will have the option to enable "Follow Me" upon launch or to enable Follow Me in the settings screen. This feature uses the devices' wireless information and provides you with the latest forecast wherever your device happens to be. Current weather conditions will update and change as your location changes as long as you have a wifi or network connection. A Follow Me location is indicated by a blue ball, and will always be the first location in the settings menu and the yellow navigation bar when enabled. Device permissions for enabling this functionality can be managed in the system settings.

4. How do I change Metric to Imperial Or from Celsius to Fahrenheit - To change from Metric to Imperial or Celsius to Fahrenheit, you will find the conversion buttons at the bottom of the settings panel. Tap the “x” in the top right corner to close it.

How do I changing the language of the app - This app supports both French and English languages. You can change the language of the app in your device system settings. From the device’s apps menu, select the settings icon. Once you are in the device’s settings menu, you can select your language.

5. How do I manage my locations?

The Weather Network App for Android allows you to add up to 10 locations. You can add or update locations in the settings menu. Simply click on the “Settings” icon in the top right corner. The Location manager lists cities, schools, parks and airports available in your area. Tap to choose one of these locations or use the search box at the top to search for other locations.

  • To add a location press the “+” symbol in the top left corner. Enter only the name of the city, school, park or airport; do not include the province or state. If searching for a city, you may enter a postal code or zip code; only Canadian postal codes and US zip codes work. For International cities enter the city name only. Once you find the location you are looking for, click on it to determine your selection and add it to your saved location list.
Locations Menu
6. How do I move between cities?

To move between multiple cities you can click on the chevrons to the left or right of the location name or you can use a swipe gesture across the top of the page.

7. What is a Widget and how do I add one?

A widget is a shortcut you can add to your Android Tablet that offers at a glance content and clicks through to the full application. Widget Managers vary by device. Please refer to the owner's manual to find out how to add and manage widgets on your Android tablet. The Weather Network widgets come in two sizes: large 4x3 and small 2x2.

Please note widgets do not update automatically with new versions of the application. If you decide to update the application you will need to manually delete the widget and add new one.

8. How do I share The Weather Network App for Android Tablet with my family and friends?

The icon in the top right of the yellow menu bar, allows you to share the app via Facebook, Twitter, Email and Google+.

9. How do I uninstall The Weather Network Android Tablet App?

We are sorry if we have not met your expectations. To uninstall The Weather Network App, please follow these steps:

  • Long Press (press and hold) The Weather Network App icon in the apps folder, drag and drop it into the red “Uninstall” icon on the top of the screen. 
  • You can also uninstall the app through your system’s settings: 
  • Settings > Applications > Manage Applications > TWM or MM > Uninstall

We hope we can offer you valuable weather services on one of our other media platforms including mobile, television or our website.

PC App FAQs+-
1. How do I get the latest Weather Network App for PC?

Download Checklist:

  • Ensure that you are not currently running another version of The Weather Network Application. The Weather Network App for PC is our latest version. If you already have the application open and saved on your computer, you will not be able to download another. To exit the application simply right click on the temperature icon and select Exit.
Uninstall TWN Mac App
  • Ensure that you are connected to the internet. An internet connection is required to get The Weather Network App files sent to your computer and gather updated weather information. 
  • System Administrator Access: ensure that you have administrative rights to download application software to your PC. If you are at home, you or the individual who set up your computer should be able to assist you. If you are at work, your IT Personnel will be able to assist. 
  • When the application asks you to Run or Save, the fastest way to download the application is to "RUN".
Run or Save 1

Run or Save 2
  • Security Pop-Ups may happen during your download process, make sure you "ALLOW" The Weather Network App to run. These security warnings are a function of your Windows Operating System (XP, Vista or Windows 7) or security software, like Norton Antivirus. It is their job to alert you when you are downloading software to ensure you want to do it. Our promise to you is that our software is safe to use and does not contain any spyware whatsoever. 
  • Are you running a firewall protector for your computer? If you are running a Personal Firewall and would like to install The Weather Network App, first make sure that the Firewall icon in the system tray is allowing incoming traffic. Once you begin the download process, the Firewall will recognize that The Weather Network is attempting to connect to your computer and will display the dialog box, "Always block connections from this program on all ports (recommended)" DO NOT SELECT OK (doing so will block the download process and any future downloads from On the screen, you will see a pull-down menu in which you will select. "Always allow connection from this program on all ports". If this popup message appears again during the installation process or during the initial startup of The Weather Network App, again select "Always allow connection from this program on all ports" prior to clicking the OK button. If during the installation process, you accidentally clicked the default selection, "Always block connection from this program on all ports" you will need to access the Personal Firewall and remove from your blocked list. You can change this setting by right clicking on the Personal Firewall icon in your system tray and then selecting Personal Firewall (at the top of the menu items). This will open up a dialogue box where you will select "Statistics" from the left hand navigation menu and then click the "View Logs" button. Within the Log Viewer window, select "firewall" from the left hand list then click on the page with the "x" through it in the top bar. Click "yes" when asked if you want to clear all log entries. To download The Weather Network App, visit and follow the prompts to download the application.
  • Proxy Servers: If you work behind a proxy server, you may have challenges downloading the application, it is best to speak with your IT support staff or service provider to determine your server settings.
  • You need Windows XP, Vista or 7 running on your PC. Unfortunately, due to hardware demands for The Weather Network App., we cannot support the app on older versions of Windows.
  • The Weather Network App. for PC uses components of Internet Explorer therefore it requires version IE7 or above. IE6 users will be issued a message suggesting an upgrade to a more recent version of Internet Explorer. Using the app on IE6 or lower will result in a degraded user experience.
PC App
  • Are you on a Mac or Linux system? The Weather Network App for PC does not work on a Linux machine at this time. We have built a separate application specifically for Macs. Please see our other apps for one that might work for you. 
  • I did not receive the new upgrade. As an existing user you should be automatically upgraded to the latest version of The Weather Network App for PC. If you are not seeing the application, it could be because the files have been moved from their original installation folder. The Weather Network App for PC files should reside here:
    Windows XP:
    C:\Documents and Settings\[user]\Local Settings\Application Data\TheWeatherNetwork\WeatherEye
    Windows Vista/7:
    If you are still having trouble accessing the latest version, please reinstall the application from here.
  • How often is the weather information updated? The Weather Network App refreshes data every 15 minutes or when the application is opened. The weather observation data can be manually refreshed if you click the Refresh button on the application window or you can press F5 on your keyboard while The Weather Application is in the open position.
The Weather Network Mac Application+-
1. How do I get the latest Weather Network App for my Mac ?

You can install The Weather Network App for Mac for the first time directly from the Mac App Store. After you have installed The Weather Network App the latest version will be pushed as an update through the Mac App Store directly to your Mac dock as indicated by the icon below. Click yes to update your App as indicated by this icon.

Weather Network Mac App

2. I’m having an issue. How can I troubleshoot?


Possible Fix

I'm receiving a No Internet Connection screen on my App.

An active Internet connection is required for The Weather Network App for Mac to pull the latest weather information. New forecast data is sent every 15 minutes when the application is running and you are connected. The Weather Network App for Mac searches for new forecast data every 15 minutes, if it has tried unsuccessfully for several times, it might time out until the next scheduled update. By minimizing or exiting the application and restarting, this should restart the scheduled update.

I don't see a cloud or sun icon and there is no temperature for my city in the task bar

For some cities, the forecast station does not supply the current weather with an observation. However, it does provide data to our forecast centre for the short and long term forecast display.

The Weather Network App for Mac is open but the information is taking a long time to load

The Weather Network App for Mac is more like a mini weather station with all the local forecast information, maps, videos and more. We do recommend a broadband connection to view the application.

I was getting data and now it's gone.

The Weather Network App for Mac is scheduled to call for data every 15 mins. To manually call for new data, click the Refresh button on the application window. The Weather Network App for Mac will get the latest information available from our servers. If you are still having issues after a significant period of time, please contact us here and we will address your concerns as quickly as possible. We apologize for any frustrations or service issues.

How do I remove the icon from the dock ?

The dock icon is installed standard with the App Store. To remove it from your dock you can drag it onto the desktop or right click on the icon and “remove”. The Weather Network App for Mac temp icon should remain in the top status bar for you to access at any time.

How do I remove the temperature tile in the top status bar ?

To remove the temperature tile in the top status bar select the power button in the top right hand corner of the app. You can also minimize the app by selecting the red close button in the top left corner. By minimizing you will still have access to the temperature tile.

3. How do I add or change my location and other default settings?

You can add up to 10 locations upon start up but if you can't think of all ten or change your mind that's ok too. Access the preferences by clicking on the gear icon, this will allow you to change or set all your default settings.

4. Advanced settings include:
  • Display on Startup (Default) - this means that each time your computer restarts, The Weather Network App for Mac will launch the full window on your screen with the latest weather information. 
  • Always On Top (Optional) - this means The Weather Network App for Mac, will also be on top of any document, email or website you have open on your computer screen. You can always minimize the applications by pressing the red close button on the left hand side of the app. 
  • Hide After (Options) - this means you can request that The Weather Network App for Mac automatically close after a certain period of time. It essentially minimizes itself. Good job The Weather Network App for Mac!
5. How do I uninstall The Weather Network App for Mac ?

We are sorry we have not met your expectations, below are instructions to uninstall The Weather Network App for Mac. Please quit the application. Please use Finder to access the Application Folder. Click on The Weather Network App for Mac icon in your Applications Folder and drag it to the trash. This should remove all files related to The Weather Network App for Mac.

Uninstall TWN Mac App
The Weather Network for Windows 8+-
1. How do I get the latest Weather Network App for Windows 8?

You can install The Weather Network App for Windows 8 for the first time directly from the Microsoft Store. After you have installed The Weather Network App the latest version will be pushed as an update through the Store.

2. How do I add a location?

Using the app for the first time, you will be presented with the Add Location screen where you can search by city name or by entering a Canadian POSTAL Code or US ZIP Code. Tap/click to choose the location and select Add.

Searching for locations

  • If you have been using the app and want to add more locations, from the forecast page select the arrow icon to the right of the location name and tap/click Add. To enter the content section from the location manager simply tap/click on one of the locations.
3. How do I find US or International cities?

You can search for US and International cities the same way you would search for Canadian cities. You can enter a location name.

4. How to I pin a Live tile?

Swipe upwards from the bottom of the screen or right click using your mouse. This will activate the lower menu bar. Select the "Pin it" icon from the right side of the menu. A pop up will appear where you can apply a custom name to the tile. Tap/click "Pin to Start". You can customize the location of each Live tile on the Windows 8 start menu, simply tap/click and drag the Live tile to the desired location.

5. The application keeps crashing, what can I do?

If The Weather Network App for Windows 8 is not running smoothly or keeps crashing, you can refresh the data by swiping upwards from the bottom of the screen or you can right click to activate the menu. Select refresh. Alternatively try exiting the application. To uninstall, first exit the application then from the Windows 8 interface tap and pull down or right click on the live tile. This will activate the lower menu where you can select uninstall. To reinstall, go to the Windows Store and download The Weather Network App again.

6. How do I change from Metric to Imperial? Or from Celsius to Fahrenheit?

To change from Metric to Imperial or Celsius to Fahrenheit, swipe/click to activate the menu on the right side of the app. Select the Settings icon to open the full menu. Chose Settings and adjust according to your preference Metric or Imperial or Celsius or Fahrenheit. Tap/click on the arrow to go back to the settings menu or simply tap/click outside the box to close it.

7. How do I find the Hourly, Short Term and Long Term forecasts?

For all locations you can access the Short Term, Long Term, 14 Day Trend and Hourly forecasts by tapping/clicking the icons to the right of the Current Condition.

Short-Term Forecast
8. Where can I find the weather news stories?

Weather News Stories can be accessed from the forecast page of all locations by swiping/scrolling to the right. Tap/click on the story you wish to read. Once you have read the article, tap/click on the arrow or anywhere outside the article to return to all of the news stories.

9. What do the different coloured lightning bolts mean?

The lightning bolt icons display when active weather is happening in that location. The live tile will show a white lightning bolt in a red box for all warnings. Once inside the app there are three different types of active weather alerts:

  • A white lightning bolt in a red box indicates that an Environment Canada alert including weather watches and/or warnings have been issued for that area. 
  • A white lightning bolt in a black box indicates that Storm Watch is in effect for that area including special coverage of the active weather event. 
  • A blue lightning bolt in a yellow box indicates active weather is occurring or will occur in that area. These events are serious but may not include an Environment Canada warning or Storm Watch coverage.
10. Security and Privacy
  • The Weather Network App for Windows 8 is not spyware or malware or adware. 
  • We do not download any "unwanted extras" to your device.
  • The weather information comes directly from The Weather Network servers located in our head offices at Oakville, ON and Montreal, QC. 
  • The secure and safe operation of your Application is of utmost importance to us; please let us know if you are unsatisfied with your service in any way.
  • For more information, please visit our Privacy Policy.
11. Demographic Information

Providing your demographic information is optional. By doing so you help us better understand our users allowing us to improve our products and services according to our audience demographics. This information is for internal purposes only. You can opt out in the Permissions of the Settings menu.

12. How do I uninstall The Weather Network App for Window 8?

We are sorry if we have not met your expectations. To uninstall, exit the application. From the Windows 8 start menu tap and pull down or right click on the live tile icon. This will activate the lower menu where you can select uninstall.

The Weather Network on TV+-
1. How can I see The Weather Network in HD?

It's pretty easy! You'll need an "HD-ready" television set – or an "HD-capable" TV with an HD set-top box – and a subscription to your cable or satellite provider that includes HD channels.

2. I already get The Weather Network in standard definition. Does that mean I get The Weather Network HD?

Not necessarily; The Weather Network HD is a separate channel. Your cable or satellite provider may include The Weather Network HD in your existing subscription, or it may be an additional option to add to your subscription package. Check the details of your cable package, or contact your provider to confirm.

3. What channel is The Weather Network HD on?

TV channel numbers – for both standard and high-definition – are set by each cable and satellite provider. To find the channel number for The Weather Network HD in your area, please contact your local cable or satellite provider, or look for the “Watch Live” icon on your city’s forecast page on the desktop website.

4. Which cable and satellite providers offer The Weather Network HD?

We’re working with cable and satellite companies to launch The Weather Network HD across Canada. Currently, The Weather Network HD is available on Rogers, Cogeco and MTS services. If you have a different cable or satellite provider, please contact them directly to ask when they’ll be offering The Weather Network HD.

5. I’m a cable subscriber, and get The Weather Network in both standard definition and HD. Why does the standard-definition channel seem to have more local weather information?

More local weather forecasts and information will be coming to The Weather Network HD soon! At this time, regional information highlights key locations in your area, but may not be as “local” as the information presented on the standard-definition channel. In early 2012, we’ll be launching fully local HD information, giving you both brilliant images and the most targeted forecasts and reporting.

6. Why is information on the left side of the screen and on the bottom being cut off?

There could be a few reasons why. The first thing to check is that your TV is set to the best viewing mode. Flat-screen televisions offer different viewing modes – for example: normal mode, zoom mode and stretch mode, etc. Check that your TV is set to normal mode. Some manufacturers use other words to describe the viewing mode options, so please keep that in mind when finding the optimal viewing mode.

Also, the factory default setting for some flat-screen TVs may cut off the sides, top and bottom of the picture (an “overscan” mode). Please consult your user manual to determine how to display the full HD size of 1920 x 1080 pixels on the screen.
7. How often is the radar picture updated in the local forecast?

The radar picture in the local forecast is updated three times an hour.

8. Where would I find news reports aired on The Weather Network?

Most news reports and features aired on The Weather Network can be found in the News tab on

9. Can I find the music that The Weather Network plays on air?

The Weather Network's music comes from a music library that is packaged for commercial use only.

10. I've just switched to satellite and my local forecasts have disappeared. What happened?

At the present time, current technology allows The Weather Network to provide local forecasts and reports to cable subscribers only through proprietary technology called PMX. PMX systems are installed in conjunction with cable companies.

Using the PMX technology, local forecasts for more than 1,200 communities across Canada are simultaneously broadcast every 10 minutes on the 10's for cable subscribers.

At the present time, this infrastructure and capability is not in place for satellite subscribers, therefore, The Weather Network broadcasts national forecasts for most major cities across the country every 10 minutes on the 10's.

Both satellite and cable subscribers receive the same "live" Weather Network broadcasts.

11. I have just switched to satellite and I no longer receive local Toronto programming. What happened?

Local Toronto programming is available to cable subscribers in the Greater Toronto Area Monday to Friday from 5:30 a.m. to 9:00 a.m. Local programming is distributed using fibre optic cables connected with cable companies in the GTA.

If you are a satellite subscriber, you will receive The Weather Network's national early morning show Monday to Friday from 5:00 a.m. to 9:00 a.m.

1. What is iTV?

iTV (interactive TV) allows you to access on-demand weather information and enhanced content with the touch of your remote. Save not only your city or town in iTV, but up to 9 other locations for your cottage, favourite vacation or a future school trip for the kids. Our weather iTV apps also show The Weather Network channel in squeeze back mode so you can easily interact with different weather info while tuning to our channel.

2. How do I get iTV?

You can access one of our iTV applications if you subscribe to TELUS Optik TV, Bell Fibe TV, Bell ExpresVu, Bell Alliant Fibre Op, MTS, Videotron illico 1, Videotron illico new generation or Sasktel. We will be launching with other providers soon. Stay tuned!

3. Is there a fee for iTV?

No. There is no fee for these interactive capabilities. You must subscribe to a Service Provider who offers our application.

4. How do I start interacting and open the application?

It's simple, simply tune into The Weather Network and press SELECT / OK on your TV remote. Depending which service you subscribe to, an iTV button may appear on The Weather Network TV channel at which point you will need to click on it first and press select to launch the application. The weather application can also be started from the Carrier's Apps menu.

5. Is it for me?

For those on the go who want quick access to weather this is a great application which allows you to personalize your weather experience. Give it a try if you haven’t already!

6. Which cities are available for me to select from?

All major cities across Canada as well as cities around the world.

7. How many favourites can I have?

You can store up to 10 favourite cities.

8. Can I leave feedback?

Absolutely. We would love to get your opinion for future enhancements or just hear your thoughts. Please email us at:

If you are a TELUS Optik TV, Bell Fibe TV, Bell Alliant Fibre Op, MTS or Sasktel subscriber you can also use your Mobile phone to scan the QR code under the Feedback tab within the application. Simply use a scanning app on your phone (such as "ScanLife") and point your phone to the TV. You will then be directed to an email screen on your phone and can start typing in some feedback. Once done just press send.

9. Can I delete a favourite city or de-select a city?

Yes. On TELUS Optik TV or Bell Fibe TV, for example, you can toggle to the City Settings button from the Main Menu and click OK. Then scroll up to Reorder or Remove and click OK. To reorder enter #s 01, 02, 03 to reorder the priority listing of favourite cities and save.

Monthly Forecast+-
1. Is this really a forecast for a whole month?

The Monthly weather tab contains three types of information, potentially; the forecast for the current day and the next 14 days, actual recorded information for the previous days in the calendar, and historical averages for the days beyond the 14 Day forecast.

2. What do the labels in the individual days mean (Actual, Forecast, Historical)?

Days in the calendar are labelled “Actual” when they are prior to today’s date. They are in the past and we know what the temperature was and how much precipitation actually fell.

Days in the calendar are labelled “Forecast” when they lie within the next 14 days. The information represents our forecast for each of these days.

Days in the calendar are labelled “Historical Avg.” when they are beyond the 14 day forecast time frame. These days contain historical averages for temperature and occurrence of precipitation.

3. Why do some days have icons and others don't?

Currently, historical cloud cover is not available. This means we do not have enough information to create an icon for days in the past and for days beyond 14 days from today.

4. What is the difference between the large temperature number and the small temperature number?

The large temperature is the highest temperature and the small number is the lowest temperature.

5. What does "feels like" mean?

Days with excessive humidity or strong winds can cause the outdoor temperature to feel warmer or cooler. This Feels Like temperature is displayed here.

6. What does POP mean on Forecast and Historical Average days?

POP, or Probability of Precipitation is created using the latest forecast and should be used as a tool to understand the likelihood of precipitation falling on any particular day in the next 14 days. 

The POP label used on days beyond 14 days in the future (Historical Average days) considers a 30 year period from 1980 to 2010 and reflects as a percentage the number of times precipitation has fallen on that day. Another way to describe it is to say that 30% of the time from 1980 to 2010, precipitation fell on that day.

7. Why do some days not have a POP shown?

If the POP for any day is below 30% than it is not displayed. This means there is a 70% chance or greater of a precipitation-free day!

8. Why do historical weather values such as temperature and precipitation not match what I observed?

Historical weather information is stored using climate zones across Canada that each location is matched with. To represent these climate zones, collections of weather stations are used to accumulate this information and they may not be in your immediate vicinity. Since weather conditions vary over short distances, cases can occur where conditions close to you may differ from the recorded values.

1. What is PointCast?

Exclusive to The Weather Network, PointCast is more than a forecast; it's your own personal forecast. PointCast provides weather information as close as 1km/0.6 miles of where you are. By using a Canadian postal code, US ZIP code or GPS on your mobile device you can access your own PointCast. With over 60,000+ forecasts an hour, The Weather Network provides detailed weather for all your favourite locations. The Weather Network is the most local and the most accurate weather provider down to 1km.

2. How does it work?

PointCasts are generated by using a combination of data inputs from global weather agencies as elements into our proprietary Pelmorex Forecast Engine (PFE). The PFE runs weather simulations and forecast models down to 1km. Our team of 40 meteorologists then refines and uses this data to create our localized PointCasts. By using exclusive technology built by the teams here at The Weather Network, we can provide a scientific forecast as close as 1km for where you are just by identifying your postal code are or using your GPS to locate. Once you have indicated your area and saved your favourites on the websites, mobile app, tablet or iTV platform, you can visit your PointCast anytime!

PointCast will offer current temperatures, 1-7 day forecasts as well as hourly and 14-day trends for over 800,000 Canadian postal code locations.

3. Where can I find PointCast? Which devices will feature PointCast?

You can find PointCast everywhere you find The Weather Network. Our websites, TV and mobile/tablets apps are all serving up PointCast information.

4. What regions will PointCast be live in?

PointCasts are all across Canada and are available in both English and French, as well as in the United States through US ZIP codes.

5. What other weather providers feature PointCast?

Only The Weather Network and has PointCast information. No other weather provider can offer you such a targeted forecast. It is exclusive technology built by The Weather Network for you.

6. How frequently is the PointCast forecast refreshed?

PointCast weather information is generated on an hourly basis.

7. What do you do with my postal code?

Postal codes are used for location based purposes and to identify your 1km area. All postal code data that is shared with The Weather Network is stored in a secure internal database at Pelmorex Media Inc headquarters. 6-digit postal code data is never sold or shared with a third party in any way.

8. What if I don't want to use PointCast, but I still want the forecast?

That's not a problem – you can still access the accurate and reliable city level forecasts always available from Canada's #1 source for weather.

9. Why aren't my selected locations being saved?

When you save a location on, a cookie is placed on your computer so that the next time you visit, the site knows which locations and postal codes are your favourites.

In order to save locations, you need to make sure that cookies are not disabled in your web browser. If you have other questions, please contact us.

Precip Start Stop+-
1. What is Precip Start Stop?

Precip Start Stop will tell you when precipitation is going to start and stop in the next 3 hours with a precision of 10 minutes. It will also provide the type of precipitation (rain, snow, freezing rain or ice pellets) and intensity.

2. How does it work & how do I use it?

Precip Start Stop is powered by a tool called Future Radar. Future Radar visualizes where rain is expected to originate and uses an algorithm to determine when precipitation is going to start and stop based on a given location. This updates every 10 minutes.

2a. What are the benefits of using Precip Start Stop?

This will be able to tell you when precipitation starts and stops, within a 10 minute range. It will allow you to plan activities with a better idea of exactly when precipitation will fall, and levels of intensity as well. Since the product updates every 10 minutes it will prove to be valuable on the days with on-and-off precipitation because it uses radar and therefore will have a better estimate on when to expect that quick passing shower in your location.

2b. Should I be cautious when using Precip Start Stop?

While this product has a lot of benefits, there are certain limitations as well. Precip Start Stop will not know if a storm is expected to grow/dissipate or change in direction. Because it interprets any radar echo as real precipitation, there is a chance that some erroneous precipitation echoes will be interpreted as rain while some very light precipitation (like super light snow in the winter) won’t be detected by the radar. Finally, this product will only work in the areas where radar data is available, as determined by Environment Canada. Areas close to the edge of the radars might not get the most accurate information. Here is a map showing the location of the radars in Canada:

Precip Start Stop B
3. Where do I find it?

A link to Precip Start Stop can be found on forecast pages for locations for which it is available (most places in Canada). For example:

Precip Start Stop C

A link is also located in the navigation dropdown under Forecasts.

4. Do the meteorologists interpret the data, similar to a forecast?

No, this product is being automatically derived from a radar. There is some further statistical automated processing done in order to increase the quality.

5. Does it have a corresponding map?

The radar map is the best corresponding map to go along with start/stop product.

6. What locations get this information?

Any location that is covered by a radar network. Please refer to radar locations map provided in question 2b. This information is available to a 1km precision, so if you are located in a bigger city, you would receive more accurate forecast details if you select your postal code, as sometimes weather can change drastically over very short distances.

7. Is it available on my mobile device and other TWN platforms?

Precip Start Stop will be added to mobile apps and the mobile website as these platforms are updated. Stay tuned!

8. Does this feature work in the winter as well? What kinds of precipitation are captured?

Yes, this product works any time of the year and it can detect any of the following precipitation types: rain, snow, freezing rain, ice pellets. While in real life it is possible to get multiple precipitation types all at the same time, this product will detect the most dominant precipitation type.

9. I am looking at the hourly forecast and it doesn’t match what Precip Start Stop is saying. How is that possible?

Hourly forecasts and Precip Start Stop have 2 different sources for its forecasts. Hourly forecasts are being produced by our meteorologists who interpret computer weather model data and use their knowledge and expertise to create a forecast. These forecasts are being updated at least twice per day and more if the forecast needs to be changed. Precip Start Stop is derived from a radar with some automated processing and is being updated every 10 minutes; hence, some differences are possible between the two products.

Forecast Information+-
1. How does The Weather Network create a local forecast?

Forecasting is complicated, and there’s a lot of pieces of data involved.

Current Weather:The observations are a report of current weather conditions at a particular time and place. Many observations are recorded at airports across the country and are a combination of data from automated weather stations and information from meteorological technicians or weather observers. An increasing number of observations come from entirely automated weather stations. Observations are generally taken at least once an hour, at the top of each hour, in Canada and around the world. However, some weather stations augmented by weather observers report only during specific times (e.g., for military flight operations). Temperature, precipitation, opacity (sky coverage), pressure, dew point, visibility and ceiling can be reported in a weather observation. However, due to equipment differences, not all weather stations report all parameters.

Forecast:The forecast is a look ahead at the expected conditions. The Weather Network’s local forecasts include a short term forecast, a long term forecast, and a 14-day trend. A short term forecast is a look at the next 24 hours broken into six-hour time blocks. The long term forecast is a look at the next two to seven days. The 14-day trend is an outlook of the expected maximum temperatures over a 14-day period compared to the average normal daily maximum. It is not unusual for the long term forecast to change daily.

The Weather Network provides both a daytime high temperature and a 24-hour minimum (or low) temperature for every day of the forecast. Usually, the highest temperature for a particular day will be achieved during the daylight hours and the lowest temperature will be during the night-time hours. However, this can change. If a warm front passes through overnight or a cold front moves through during the day, the highest or lowest temperature may occur at an unusual hour.

Probability of precipitation (POP) is one of the most misunderstood elements of any forecast. It is simply the chance that measurable precipitation will occur at a particular location over a given time period. Measurable precipitation means at least 0.2 mm of rain or the water equivalent of snow. The POP does not predict when, where or how much precipitation will occur. Therefore a POP of 30% means that there is a 3 in 10 chance that there will be measurable precipitation at the location. A POP of 100% means that the forecaster has a very high confidence that rain will fall at the forecast location. These high POP values are associated with very organized weather systems covering large areas of the country. On the other hand, thunderstorm forecasts are often associated with lower POP values such as 40%. In this case, there is a better chance that the location will stay dry vs. getting wet. People who can be flexible with their plans should not cancel outdoor activities, but must be ready to quickly take cover if a thunderstorm does develop.

A wind forecast includes direction and speed. The strength and direction of the wind is the result of pressure differences in the atmosphere which are caused by large areas of high and low pressure as well as local effects. On a surface weather map, the distance between the isobars (lines of equal atmospheric pressure) can be used to judge the strength of the wind – the closer the isobars, the stronger the wind. Generally, air circulates clockwise around high pressure and counter-clockwise around low pressure in the northern hemisphere. Although some local effects are taken into consideration when generating a wind forecast, winds can be affected by urban structures such as buildings. Urban structures are not considered when formulating a wind forecast for a particular city as wind speed and direction can vary significantly around a given building.

The humidex is an index which accounts for the combined effect of the temperature and humidity. The humidex is not a temperature, but attempts to give a value which reflects a person’s perception of discomfort when warm temperatures are coupled with moderate to high humidity. Generally, people begin to perceive the effects of temperature and humidity when the humidex exceeds a value of 29. The wind chill is an index which accounts for the cooling effect of the wind at low temperatures. The wind chill is not a temperature, but reflects the feeling of colder conditions when your skin is exposed to wind. The index was determined by comparing the rate of heat lost from a person’s face under different temperature and wind conditions. It gives an idea of the temperature under nearly calm conditions which would cause your face to feel the same cold sensation as the actual temperature and wind. It is important to understand that the wind chill is not a temperature, and that your skin, or any object, cannot be cooled below the actual air temperature. The wind chill is a calculation which appears on The Weather Network when the wind chill drops below 0.

The normal maximum or minimum temperature is an average daily high or low temperature for the time period and is based on an average of 30 years of data. The daily normal or mean temperature refers to the average of the daily maximum and minimum temperatures for a particular day, month or year based on 30 years of data.

2. What time frame is meant when referring to morning, afternoon, evening, and overnight forecasts?

The short term forecasts created by The Weather Network are based on six hour time periods. The breakdowns are:

  • Morning: 6 a.m. - 12 noon 
  • Afternoon: 12 noon – 6 p.m. 
  • Evening: 6 p.m. - 12 midnight 
  • Overnight: 12 midnight – 6 a.m.
3. Why is there a difference in forecasts from The Weather Network and Environment Canada?

Forecasts that are prepared by different forecasters will sometimes vary. When looking at satellite, radar and computer model data, different people will interpret the data differently. Although meteorology is a physical science based on mathematics, the science is so complex that a number of outcomes are possible. It is akin to when two market analysts look at the economy, they may interpret historical information differently and predict varying outcomes. At The Weather Network, we employ more than 40 meteorologists working 24/7 to ensure that our forecasts are as accurate as possible.

4. Why does the forecast change?

The Weather Network's forecasts are regularly updated during the day to ensure that Canadians have access to the most accurate, local forecasts for their planning needs. Using computer models, our team of professional meteorologists is always on the lookout to see if:

  • weather systems are picking up pace, reducing speed or changing direction; 
  • the moisture in the system is changing; 
  • and whether the system is gathering strength or losing its intensity.

When our meteorologists become aware of significant changes in the atmosphere, they will issue an updated forecast based on the recent developments.

5. Why are there sometimes differences between weather warnings and forecasts?

Environment Canada weather warnings are based on a sudden change in weather systems and are short-lived. Forecasts are simply a look ahead at the expected conditions. Our meteorologists upgrade the forecasts according to the changes in weather.

6. How can the forecast for my area suggest not to expect any precipitation from Thursday afternoon to Friday afternoon while at the same time having a snow squall warning that says we will get between 15-25 cm in that same time period?

Weather warnings are issued by Environment Canada. The Weather Network has separate forecasts from Environment Canada which are very local for each community. We use Canadian computer models to base our forecasts on, and two American models for comparison. Generally, a warning will be applied to a larger area than just your community, and it is possible to see some differences between our local forecast and the weather warning. Snowfall amounts within snow squalls are particularly difficult for meteorologists to forecast. If the wind shifts even a little bit, snow squalls and higher-than-expected snow amounts could occur, that weren’t predicted by the computer model or the forecaster. The local snow amounts can vary greatly depending on exactly where you are and which direction and speed the wind is blowing.

7. What is the difference between partly cloudy and partly sunny?

These terms are often misunderstood. Forecasters have disagreed over the definition of "partly" for years; that's why it is not widely used. In forecasting sky conditions, meteorologists describe what percent of the sky, from horizon to horizon, rounded to the nearest 10, is expected to be covered by clouds. A sunny day is one when there are no clouds or only 10 percent of the sky is expected to have cloud. With 20 percent or 30 percent cloud cover, the forecast calls for mostly or mainly sunny, or sunny with cloudy periods. When more cloud than sun is forecast, say 70 to 80 percent cloud cover, it's mostly or mainly cloudy, or cloudy with clear periods, or cloudy with sunny breaks. When 90 percent or more of the full sky is covered by cloud then it's a cloudy or overcast sky. When it's about half cloud and half blue sky, the wording is “mix of sun and clouds” or “variable cloudiness”.

8. What is the difference between a shower, a period of rain, a rain shower and a trace of rain?

The difference between rain and rain showers has to do with the duration of the event and cloud type involved. For rain, which can last from a few hours to days, the cloud formation has to be more stratiform (horizontal) in nature. That is not to say that convective events cannot be associated with areas of rain. Rain showers are usually short in duration, a few minutes to an hour and are the product of convective activity. You get rain only on cloudy days but can get showers on somewhat sunny days due to convective or bubbly cloud formations such as towering cumulus or cumulonimbus type clouds. The term “trace” is used for rainfall amounts of less than 0.2 mm – this amount of rain isn’t enough to completely wet pavement, and generally does not disrupt outdoor activities.

9. How often are weather observations taken?

Environment Canada holds agreements with the World Meteorological Organization (the world’s standardizing body for meteorology) to take observations once an hour in fair or quiet weather. When more severe weather, such as strong gusts, hail, or freezing rain comes in, the observations are taken as often as necessary to alert the public of sudden, dramatic weather changes.

10. Why are sky conditions not available for some locations?

Weather observation sites at airports in Canada are operated by NAV Canada (the country's civil air navigation services provider) on behalf of Environment Canada. Generally, sky conditions are reported at these sites unless there has been a malfunction. Many weather stations not located at airports do not have the necessary instruments to record current precipitation and cloud conditions.

11. How are meteorologists able to predict the amount of snow or rain that will fall?

The numerical forecast models used by meteorologists contain what is called QPF (quantitative precipitation forecast) information. This water equivalent can be converted to snowfall by use of certain mathematical formulas. Meteorologists also look at weather observations and use their experience to modify the quantitative precipitation forecast information from the computer models to produce the most accurate forecast of a snow or rain amount.

12. Is the air pressure shown on the local forecasts a corrected figure or uncorrected? How do you convert one to the other?

The pressure on the local forecasts is corrected to reflect the mean sea level pressure. If you look at your barometer at home (unless you live at sea level), it will actually read at a lower pressure. The mean sea level pressure that we report is not the actual atmospheric (or “station”) pressure at a given location, but rather a calculated value of the pressure if that location were at sea level. It is meteorological convention to speak of pressure as a mean sea level pressure for comparative purposes. However, for any practical calculation at a given location, the actual station pressure would be used.

The reason we correct pressure readings to mean sea level is so that we can compare locations at different elevations more easily (an example of this would be a surface weather map showing isobars – these lines connect areas of equal mean sea level pressure and help us identify areas of high/low pressure). If we did not do this, it would be more difficult to judge the relative strength of an area of high or low pressure as the system moved from a high elevation mountainous region into a low elevation region.

Cold weather +-
1. Why is the coldest part of the day just after sunrise?

During the night-time hours, the atmosphere’s heat is lost to space and the earth cools. When the sun comes up, solar radiation is initially very weak since the sun is very low in the sky. Meanwhile, energy is still being lost to space. As a result, during the first few minutes after the sun rises the energy outgoing to space exceeds the energy incoming from the sun so the temperature continues to drop – reaching the daily low typically within about 15 to 30 minutes after sunrise. As the sun reaches a point slightly higher in the sky, the amount of incoming energy equals and then exceeds the amount of outgoing energy and the temperature begins to rise.

In perfectly clear and calm conditions, another effect may play a role in decreasing the temperature after sunrise. Thermometers generally measure air temperature a couple metres off the ground. On clear, calm nights, the layer of air closest to the ground may be noticeably colder that the air around the thermometer. As the sun begins heating the ground, this colder layer of air is stirred slightly and rises to the thermometer level.

2. How can snow keep you warm?

Snow can keep you warm because it is one of the world's best insulating materials. Dry fluffy snow is about 95% air. With all the air spaces, snow prevents heat loss just like fiberglass insulation or styrofoam. The temperature contrast between the top and bottom of a snow layer is often striking. For example, on a cold night, at the top of a snow cover the air temperature might be -30°C or lower. With a snow pack of 40 cm, the ground temperature might be around -6°C, making a difference of nearly 25°C between the top and bottom of the snow cover.

Without the protection of snow, the ground would freeze solid and vegetation in some parts of Canada would not survive the winter. Small mammals like mice, squirrels, rabbits and hibernating insects are able to live cozily through periods of brutally cold temperatures. During snowstorms, large animals will tunnel into snow banks, thereby greatly decreasing the rate at which their bodies lose heat. In the same way, a covering of snow provides an insulating blanket on your flowerbeds and on your roof, holding heat in when the air temperature drops well below freezing.

3. Is it too cold to go outside when the temperature is -12°C with the wind chill factor?

You can go out with a wind chill of -12°C. Just make sure you are properly dressed in a warm winter coat and that your hands, ears and head are properly covered from the wind and cold. You may want to try layering your clothing since it is one of the best ways to insulate your body.

4. What freezes faster, hot water or cold water?

The answer to this seemingly simple question isn’t straightforward! While the exact reason isn’t fully understood, hot water can freeze faster than cold water under certain conditions. The effects of convection within the container and the ability for water to become supercooled (still remaining liquid at temperatures below freezing) are thought to play an important role in the cases where hot water freezes more quickly. However, additional factors such as the initial temperature of the water, shape and size of the containers, water purity and air temperature may all contribute to the outcome. You can try this experiment yourself by filling two ice cube trays with hot and cold water and putting them in your freezer. Because there are so many variables in this experiment, you may get different results than your neighbour!

5. If it's 3°C outside with a windchill factor of -8°C, will water freeze due to the windchill factor?

No. The freezing point of pure water is, as you know, 0°C. If the air temperature is not at or below this temperature, the water temperature will also remain above freezing and the water will not freeze. Water in an environment where the air is at 3°C cannot get colder than 3°C no matter what the wind is doing. In fact, even if the wind is howling and the water is already frozen the ice will melt and the water will warm to 3°C over time. The reason people and other warm blooded animals feel colder due to the wind is that we generate heat internally as we metabolize food and fat. When the wind is blowing and the temperatures are cold enough (as opposed to a hot summer day) our bodies lose this internally-generated heat as the air flowing around us carries the heat away. At a given temperature, the stronger the wind is the faster this heat loss occurs and the colder we feel. The wind does not actually make the air colder so it can not cause water to freeze if the temperature is above 0°C.

Satellite and radar+-
1. Why does the radar map almost always show precipitation over the same area, even when it is clear?

Radar stations located across Canada and the U.S.A. continually sweep the sky, sending out beams of microwave energy that bounce off precipitation particles. The radar antennae measure the amount of energy that is reflected back from these particles and we plot this information on a map as the precipitation intensity. However, energy sent out by the radar also bounces off the ground, buildings, bugs, mountains, etc. – we call these unintended targets “ground clutter” or just clutter. While it is possible to filter out most of this ground clutter, some of it will still be plotted on the radar map.

2. Given the advent of radar- and satellite-based atmospheric measurements, do we still utilize individual weather station data?

Meteorologists continue to use surface weather stations because they are the best way to measure the conditions at a specific location. While all instruments are prone to some degree of error, the observations from a surface weather station are considered to be the best available. However, radar and satellite data is extremely valuable because it allows meteorologists to see the weather over vast areas where it is not possible to place surface weather stations. In weather forecasting, a mix of all data, both remotely sensed (radar and satellite) and in situ (weather stations) is critical to producing an accurate forecast.

3. Why it is that sometimes the satellite image over Atlantic Canada looks quite ominous when there is very little precipitation – while at other times, it is indicative of a large low pressure system, typically a storm. Why the discrepancy?

Satellite images are snapshots of clouds and, depending on the weather situation, the clouds displayed may not produce precipitation that will fall to the earth. There are three primary types of satellite images used by meteorologists: visible, infrared and water vapour. Most often, the infrared satellite image is shown on weather maps. On an infrared image, the coldest and highest cloud tops are usually enhanced to draw our attention to these areas. Cold, high cloud tops are usually associated with large storm systems as well as thunderstorms, but can also be simply high cirrus clouds with no precipitation. Satellite imagery is a very important tool, but we need to use other tools such as radar, surface weather stations, and numerical computer models, to predict if a system will actually bring precipitation.

Precipitation +-
1. How do you know if it is going to rain? What is meant by the “POP”?

Determining if it will rain depends on many factors such as a storm’s track, the amount of moisture the storm has, the speed of rising air in the storm, and the temperature before, during and after the storm. After analyzing these and other factors, the meteorologist then looks at the chance rain will occur. This chance is expressed as “Probability of Precipitation” (“POP”).

The POP does not predict when, where or how much precipitation will occur. Therefore a POP of 30 percent means that there is a three in 10 chance that there will be measurable precipitation at the location. A POP of 100 percent means that the forecaster has a very high confidence that rain will fall at the forecast location. High POP values are associated with very organized weather systems covering large areas of the country. On the other hand, thunderstorm forecasts are often associated with lower POP values such as 40 percent. In this case, there is a better chance that the location will stay dry. People who can be flexible with their plans should not cancel outdoor activities, but must be ready to quickly take cover if a thunderstorm does develop.

2. Why does hail make its particular sound?

Hail’s particular sound is the combination of many hailstones falling through trees, on roofs and on the ground at some distance upwind from you. The mingled noises made by these fallen hailstones arrive to your ears ahead of the storm itself. Once the storm arrives where you are, the patter of individual stones drowns out the noise from distant hailstones, some two or three kilometres away.

3. Are raindrops really tear-shaped?

Raindrops are shaped more like mushroom tops, round baseballs or hamburger buns. The falling speed of a raindrop is directly related to its size. Small drops, those less than 2 mm in diameter, tend to fall more slowly and remain round while larger raindrops, which fall more quickly, take on a more oblong shape due to the air pressure pushing up against the bottom of the drop.

In larger raindrops (more than 4.5 mm in diameter),the bottom of the raindrop encounters much greater air pressure than the top which will eventually cause the large drop to break apart into two smaller raindrops.

4. Why are snowflakes quite big on certain days, and then smaller on other days?

The shape and size of an individual snowflake depends on the air temperature and the amount of water vapour available in the cloud where the snowflake forms. In very moist situations where snowflakes fall through a large depth of air near 0°C, the snowflake that reaches the ground can be a combination of dozens of matted-together smaller flakes. Snowflakes that form in drier conditions do not join together as easily and therefore, fall as individual smaller flakes.

Nearly anything can happen to a snowflake as it falls to the earth. These include pieces of a snowflake breaking off, evaporating into the atmosphere, and joining other falling snowflakes. Additionally, if the wind speed is too great, bigger flakes will be ripped apart and most of the snow will fall as smaller flakes.

5. Can snow have different colours?

Snow can appear to be many different colours. Most often, it appears white due to the equal reflection of all wavelengths of sunlight off the ice crystals and air pockets within snow. However, snow can contain much more than ice and air. Pollen, single-celled organisms, specks of dust, dirt, sand, ash and traces of pollution are sometimes in sufficient quantities to affect the colour. Additionally, colonies made up of algae, fungi, and bacteria living among the crystals feed on the nutrients in the snow. Over the centuries, there have been reports of different coloured snowflakes from around the world. In 1818, Arctic explorer Sir John Ross discovered large deposits of red-coloured snow in Greenland. It was found to contain red-tinted, microscopic plants and animals. Yellow snow from can be created from pollen in a nearby pine forest; pink snow has fallen on Vancouver Island; and pale-blue snow has been seen in the French Alps – presumably coloured by copper salts in the dust from the Sahara desert. During the Dust Bowl in the 1930s, black and brown soils from Oklahoma and Texas turned snow non-white in many places throughout Eastern Canada.

6. Why does snow squeak when you walk on it?

The colder the temperature, the fluffier the snow and the squeakier the sound it makes when you walk on it. On cold days, when the temperature is -15°C or lower, there is less liquid water around the ice crystals to lubricate them as they move. Instead, when you step down, the individual cold ice crystals move abruptly, slipping and crashing into each other. The sudden rubbing or smashing produces that familiar cold-weather creaking sound. Because the sound produced by snow is related to how cold it is, you can use it to tell the temperature. The louder the snow noise, the colder the temperature of both the air and snow. When the snow cover is hard-packed or crusty, a distinctive crunching sound is heard when you step down. This crunching sound is caused by the breaking of strong bonds between ice grains within the snow pack.

7. Which day is the snowiest?

Day-of-the-week variation in weather always produces lively discussion. Generally, there is little correlation between the day of the week and the likelihood of snow, or the amount of snowfall. Over time, the random nature of the timing of large weather systems will tend to make the chances of seeing snow equal for all days of the week.

Some studies in Australia and France have found variations in weekday vs. weekend weather. The theory is that increased air pollution on weekdays, especially in heavily populated areas, may alter the formation of precipitation by producing a greater abundance of condensation nuclei (particles that rain and snow form around). However, the impact is most likely very small, and would not significantly affect the amount of precipitation from large storm systems.

8. What do you call it when snow evaporates before hitting the ground?

Virga is snow, or any precipitation that evaporates before hitting the ground. It is common in places where the atmosphere is especially dry in the first one kilometre above the ground.

9. When is it too warm to snow?

Generally, outside of mountainous regions, it is too warm to snow at 5°C. However, there are extreme cases where snow has been observed when the temperature is warmer than this. In these cases, there is a very shallow layer of warm air near the ground and the temperature decreases very rapidly going up (the clouds where the snow forms must be well below 0°C). The warm layer of air is not deep enough to completely melt the snowflakes before they reach the ground. If snow keeps falling for more than a few minutes, the temperature will usually fall quickly because of the heat being consumed by the melting snow.

10. What determines whether precipitation will fall as freezing rain or snow?

Our atmosphere is composed of layers of air with different temperatures. So, air temperature at the earth's surface may be different from that above. What determines whether you get freezing rain, ice pellets, snow, or rain, is the thickness of warm and cold air over your region as well as the surface air temperature.

For example, freezing rain is possible when warm, moist air with temperatures above 0°C is sandwiched between two colder layers of air below 0°C. Precipitation from higher, colder levels begins falling as snow. As it falls through the warmer layer in between, the snow melts into raindrops. The warm layer should be over 1 km thick with temperatures above 0°C in order for the snow to melt. The precipitation now enters the sub-freezing surface layer and becomes super-cooled rain (raindrops below 0°C) which then freezes as it falls onto objects on the ground. If the warm layer is not deep enough to melt all the snow flakes into raindrops, partially melted snowflakes will refreeze in the subfreezing layer before reaching the ground, creating ice pellets. Because of the different sizes of snowflakes initially produced high in the cloud, a mixture of ice pellets and freezing rain often occurs when a warm layer of air in present in a winter storm.

The thicknesses and temperatures of these warm and cold layers above the ground constantly change during a storm, making the exact timing and amount of each precipitation type very difficult to forecast.

11. Why are all snow flakes six sided?

The water molecule is the key here. The water molecule is made up of two atoms of hydrogen and one atom of oxygen and if you could look at it, you would see that they hold the shape of a triangle. As an ice crystal begins to form, water molecules arrange themselves in a way that forms a hexagonal lattice. This six-sided structure is reflected in the larger ice crystals and snowflakes that we see. While snowflakes can take on many different shapes and are often irregular in appearance, their formation is based on this six-sided structure.

12. Can it ever be too cold for it to snow?

When the air temperature gets well below -30°C, there is very little water vapour available to produce significant snow. Ice crystals do form at very cold temperatures below -40°C so technically it can’t be too cold to snow. However, practically speaking, no significant snow will occur at these temperatures.

13. Why does it snow at all when it's above zero degrees?

Snow falls when temperatures are above zero degrees because much colder air is located aloft in the clouds where the snow is produced. The shallow layer of air near the ground may be above zero but this layer is usually only a few hundred metres thick. The snow that falls into this above freezing layer does not have time to melt completely before reaching the ground. Generally, snow will not accumulate if the air temperature at the surface is above freezing. However, if snow is falling heavily enough, it is possible for the snow to accumulate, even though the air temperature is slightly above freezing.

El Niño+-
1. What are El Niño and La Niña?

El Niño and La Niña are phases of the climate cycle called the El Niño/Southern Oscillation which describes the ocean and atmospheric patterns occurring in and over the equatorial Pacific Ocean. El Niño is characterized by warmer than normal sea-surface temperatures west of South America that endure for several seasons, whereas La Niña represents the opposite, cooler phase. Changes in water temperature across vast stretches of the Pacific Ocean cause disruptions in the tradewinds and weather conditions. Both phenomena have a large impact on the jet stream and weather patterns around the world that can result in floods or droughts. El Niño events vary in intensity and recur every two to seven years. The term El Niño (“the boy-child”) was originally used to describe a local ocean current which occurred around December off the coast of Peru and Ecuador, but was later applied to a periodic warming of these coastal waters which affected the local ecology. While these meanings are still used today, the term El Niño has become more commonly associated with the larger periodic warming of the central and eastern Pacific waters and the corresponding changes in global weather patterns.

2. How do El Niño and La Niña affect our weather?

The periodic changes in the Pacific Ocean water temperatures that define El Niño and La Niña can impact weather patterns around the world. The effects are more prominent in countries surrounding the Pacific Ocean and are most noticeable in the winter and summer months. During El Niño episodes, drier-than-normal conditions can affect much of South Asia and Australia while wetter and warmer-than-normal conditions occur across southern and western South America. During La Niña episodes, wetter-than-normal conditions can last for many months across South Asia and Australia while cooler-than-normal weather prevails in parts of South America.

In Canada, El Niño's impacts are most clearly noticed during winter in western Canada. While the southern United States sees cooler and wetter conditions, western Canada often experiences mild winters during an El Niño episode. Depending on the strength of the El Niño, milder-than-normal conditions may extend through Ontario, Quebec and towards Atlantic Canada. The opposite is true for La Niña episodes where colder-than-normal winter temperatures with heavier precipitation is seen, especially across western Canada.

3. Is it possible to get a forecast for El Niño for next winter?

El Niño is a cyclical event that occurs every two to seven years lasting five to 18 months. Generally, El Niño conditions can be predicted with some success three to six months in advance. However, the strength of an El Niño or La Niña event is difficult to predict more than a few months in advance.

4. What does history tell us of weather conditions following an El Niño year? Specifically, what is its effect in relation to western Canadian agriculture?

Every El Niño presents a different situation for specific places in western Canada. However, an El Niño winter generally causes the growing season to start off drier and warmer than usual.

5. Is El Niño getting blamed for weather it does not affect? For instance, can El Niño affect the weather inland?

El Niño affects global weather patterns, but has its greatest impact on countries that border the Pacific and Indian Oceans where changes in water temperatures have the greatest influence on the weather pattern. El Niño episodes can influence the jet stream pattern which may result in a warmer than normal winter across the Great Lakes, for example, but the exact impact depends on the intensity of the episode, and other circulations in the atmosphere. While El Niño and La Niña do affect global weather patterns, these phenomena do not directly cause individual storm systems which are the result of smaller circulations within the global jet stream pattern.

1. What are the types of clouds and how are they formed?

The visual appearance of clouds is defined in four primary groups:

Cirrus: High clouds made of tiny ice crystals. They look like fine, wispy white strands of hair. Stratus: Layered, generally flat clouds. Stratus clouds can occur at various altitudes and can be thin or thick.
Cumulus: Distinguished from stratus clouds by the fact that they are not flat and have a heaping appearance. Smaller cumulus clouds look like white cotton balls and are made up of billions of tiny water droplets.
Nimbus: Clouds that are accompanied by rain.

Clouds are further classified according to the height of the cloud base:

High-level clouds: The prefix "cirr" is used to describe high clouds. The primary types include cirrus, cirrostratus and cirrocumulus.
Mid-level clouds: The prefix "alto" is used to describe mid-level clouds. The primary types include altostratus and altocumulus.
Low-level clouds: Examples of low-level clouds include stratus, stratocumulus and nimbostratus.
Vertically developed clouds: These are clouds which generally have low cloud bases, but also have significant vertical height relative to their width. Examples are cumulus, towering cumulus, and cumulonimbus.

2. Why don't clouds fall from the sky?

Those puffy, fluffy fair-weather clouds, known as cumulus clouds, are heavier than you might think. Take a single cloud about 1 km wide and 1 km long, and about as high as it is wide. Weigh all the cloud's liquid water, and you'll find it is weighs about 500 tonnes - more than a 747 jetliner fully loaded with passengers and fuel.

Because clouds are composed of light, tiny droplets - you'd need to collect more than 2 billion droplets to make a teaspoon of water - it doesn't take a lot to hold them up.

Clouds are suspended in the air by the lifting action of air currents (winds deflected from hills and mountains) but especially by convection, warm air rising from the surface of the earth. When the sun sets, these rising air currents quickly lose their heat source and constant force. Cumulus clouds in particular begin to descend as air currents cool, yet instead of descending all the way to the ground, the air in the clouds actually warms and starts to become drier, causing the droplets to evaporate. The clouds literally disappear before they reach the ground.

3. How do holes form in clouds?

Sometimes invisible falling streaks of ice crystals from higher clouds are intercepted by thin, lower cloud composed of water droplets. The water droplets evaporate as the ice crystals grow in the saturated air within the cloud. The ice crystals then fall from the cloud and leave an almost perfectly circular hole. Evidence also strongly supports the suggestion that passing aircraft punch holes in thin clouds. Airplane exhaust produces ice particles, and in time, these ice crystals become large enough to fall out and eventually evaporate. Also, engine heat and turbulence along the wing tips mixes moist and dry air causing clear holes.

4. Under what conditions can we expect stratus clouds? Are these convective clouds?

All clouds form when the surrounding air temperature cools down to the dew point temperature for the air mass. When this happens, water droplets form and appear in the sky. We call this group of droplets in the sky a cloud. An example of this effect can be found near the earth's surface in the formation of fog when the air temperature near the ground is equal to the dew point. When fog lifts up off the ground but remains a few hundred metres above the surface, we call it a layer of stratus clouds. Stratus and fog are not convective clouds. Stratus commonly occurs over the Pacific or Atlantic coastal waters in the summer and over open bodies of water in the spring and fall. In general, there is less convection in winter except near warm bodies of water that may cause local convection to occur and bring on snow squalls.

5. Why is it that in METARs (Aviation Routine Weather Reports), we often see a first layer of stratus fractus clouds and a second of stratocumulus clouds? Wouldn't cumulus fractus and stratocumulus be more appropriate?

METARs describe clouds, or the various layers of clouds from the ground up. Often near the surface, there are bits of stratus cloud floating around but not enough for a complete deck of stratus. This gives the first layer a broken appearance, hence the name stratus fractus. Above this fractured layer, we find the more convective layer of clouds. If this convective layer is in the lower atmosphere, we call it stratocumulus (SC). Cumulus fractus (CF) should be used to describe widely scattered cumulus clouds.

6. Why can clouds appear extremely dark when they are approaching yet lighten up when they are above us?

The colour that clouds appear to be has more to do with their type than their location. Clouds laden with abundant moisture, i.e. formed with many droplets, will tend to be relatively dark since water droplets in the cloud will absorb light passing through it. Clouds such as cirrus that we see as thin streaks high in the sky, or cirrocumulus, that we see as small, round white puffs, contain relatively little moisture. In fact, cirrus clouds are almost exclusively composed of ice crystals. Clouds such as altocumulus, also known as middle clouds, are composed mostly of water droplets that appear as grey, puffy masses. Another fact determining the appearance of clouds is their position relative to the viewer and the sun. When the sun is visible, an approaching thunderstorm may look especially dark because of the contrast between the bright foreground lit by the sun and the dark background where the storm is located. When the storm begins to obscure the sun, the storm cloud may not appear as dark because of the reduced contrast within the field of vision.

Weather Systems+-
1. Are there more tornadoes these days?

This is a difficult question to answer because the number of official tornadoes each year is really just the number of tornadoes that we have record of due to sightings or damage. This number has increased. For example, there was three times the number of tornadoes in 1990, than in 1953. However, these numbers may not represent an actual increase in the number of tornadoes but may instead be due to a higher percentage of tornadoes being seen and reported.

Today, population density is more widespread than in the past, with police, highway crews, farmers, fishermen and weather volunteers paying much more attention to severe weather. The general public is more alert to the dangers of severe weather, especially tornadoes. Improved technology has also had an impact with many more eyewitness accounts by people armed with cameras and cellphones. Greater numbers are also reflected through better radar systems and weather satellites.

As our awareness of severe summer weather increases, the tornado count will likely increase as well – even though the number of actual tornadoes may not necessarily be increasing.

2. What are cyclones?

For many years, the word cyclone was widely misunderstood to mean only a twister or tornado. “Cyclone” is actually a generic term that describes low pressure systems ranging in scale from tornadoes and tiny dust devils to monstrous hurricanes and typhoons. It comes from the Greek word, “kyklon,” meaning cycle, circle or coil.

All cyclones have winds which converge inward toward a centre of low pressure. Apart from that similarity, the family of cyclones includes many different types of low pressure systems with differences in where they form, size and effects. Even though the word is very loosely applied to any strong wind today, it is usually reserved for huge, intense tropical low-pressure systems including: high wind and heavy rain storms called hurricanes in the Eastern Pacific and the Atlantic; typhoons in the Western Pacific; and cyclones in the Arabian Sea and in the Indian Ocean around Australia.

3. When and how often do hurricanes happen in Canada?

Hurricanes that develop in the tropics and move up the eastern United States coastline mainly affect Atlantic Canada. Usually by the time they get to Atlantic Canada, these systems have weakened into tropical storms or transitioned into “post-tropical” storms which take on features like fronts and a broad wind field similar to our typical mid-latitude low pressure systems. It is rare for hurricanes to maintain hurricane strength when they reach the Maritimes and Newfoundland but it does happen and the peak time is September and October. Canadian waters are typically affected by tropical cyclones every year, with hurricanes affecting Canadian waters every few years.

4. What is the most popular hurricane name?

Different naming rules are used in different ocean areas. In the Atlantic Ocean, the practice of naming tropical storms using female names was started in 1953. Male names were first used in 1979. Today a United Nations weather committee rotates six separate lists with alternating female and male names in alphabetical order. They chose names that are common in French, English or Spanish, are easy to pronounce and have fewer than ten letters. Names of violent, very destructive storms such as Katrina and Juan are retired from the list. The names most often given to a tropical storm or hurricane over the years are Anna/Ana and Arlene.

Some other hurricane name facts:

  • The first female name was Alice; first male hurricane was Bob. 
  • The first female names retired were Carol and Hazel in 1954; the first male name retired was David in 1979.
5. How are twisters formed?

Twisters or tornadoes are still one of the most elusive creatures of the atmosphere. Although our understanding of tornadoes has improved over the years, we still do not have a complete understanding of how they form.

Most tornadoes form in severe or intense thunderstorms. In these storms, warm moist air at the surface rises rapidly as it converges into the centre of the storm due to the presence of cold, dry air aloft which makes the atmosphere very unstable. The other main ingredient is wind shear, which is a change in wind speed and direction with height. As the air rises, the wind shear is tilted from the horizontal into the vertical which creates an area of rapidly spinning air. As air continues to converge into the storm centre and accelerate upward, this spin is stretched vertically while shrinking horizontally which causes the winds to rapidly increase, similar to what happens as an ice skater draws her arms in. The funnel cloud forms when the moisture in the rising air condenses. When the spinning funnel cloud reaches the surface it is called a tornado.

6. Why do some tornadoes form a “straight” funnel between the earth and the base of the cloud and some a more curvy “S-shaped” funnel?

Every tornado forms from a severe thunderstorm, and even though scientists do not have a complete understanding of how they form, videos and camera shots show us that most tornadoes have a similar lifecycle. A tornado starts as a small wedge-shaped funnel from the base of a severe thunderstorm and works its way down to the ground. Once it touches the ground and starts to draw in all kind of debris, the funnel becomes more visible, widens and looks like a “straight” vertical funnel. As it proceeds further into the life cycle, it begins to change its shape and “slithers” until it dissipates.

7. What determines the diameter of the actual funnel, as some tornadoes seem narrow and some seem to have a massive funnel?

The massive wedge shaped tornadoes are formed in exceptionally strong thunderstorms. All storms are different, but smaller thunderstorms will usually produce thinner tornadoes that appear to “slither”.

8. What does it mean when the barometric pressure is rising or falling?

Rising barometric pressure generally indicates that an area of high pressure is approaching. Falling barometric pressure generally indicates that an area of low pressure is approaching. Because high-pressure areas are generally associated with fair weather, and low pressure with clouds and precipitation, one can expect those types of weather conditions depending on what the barometer is indicating.

9. What is the difference between a thundershower and a thunderstorm?

There is no difference. Meteorologists classify these storms as "thunderstorms" or "severe thunderstorms" and the classification of the severe thunderstorm varies from region to region, and from province to province. Some people use the term “thundershower” to describe a weak thunderstorm. Weak thunderstorms, however, can still cause damage.

10. What’s the difference between a snow squall and a blizzard?

There are a number of differences between a snow squall and a blizzard. A blizzard generally meets these conditions:

  • Winds must be sustained at 40 km/h 
  • Visibility is less than 1 km due to falling or blowing snow 
  • The wind chill value is greater than 1600 watts per metre squared, or the temperature is at least -25°C or colder
  • The above conditions must be met for a minimum of four hours 
  • There does not need to be snow falling during this event

For a snow squall, the main difference is the duration of the event and that falling snow is required – with the rest of the above conditions. A squall is generally defined as the sudden onset of strong winds of at least 22 knots or around 39 km/h for approximately one minute.

11. How can snow fall in Mexico when we have warm temperatures and no snow in Canada?

In winter, large undulations can develop in the jet stream, known as troughs and ridges. In a deep trough the jet stream dips far to the south before curving back towards the north. This can bring cold and snow to places like Texas and the mountainous regions of Mexico, despite their southern location. Often when there is a big dip in the jet stream, or trough, there will be a compensating area downstream where the jet stream bulges far to the north – forming a ridge. Areas under this ridge, such as the eastern Great Lakes, often experience warm temperatures with no snow despite being farther north.

12. I heard that weather moves from west to east, such as from western Canada to eastern Canada (maybe 4-5 days later) and then another 4-5 days to England and France. Is this true?

Yes. Most of the time weather does move from west to east, with some variation. For example, sometimes our weather moves from the northwest to the southeast or from the American Southwest into the Canadian Northeast. The main reason for these variations is the position of the jet stream. On rare occasions, however, large “blocking” areas of high pressure aloft develop in the northern latitudes, particularly over the northern oceans such as the north Atlantic. When this happens the clockwise flow around the high can move weather systems in the opposite direction – from east to west.

13. On average, how long does it take a weather system to move across the continent?

On average three to five days. The movement of weather systems across the continent is determined by a number of factors, such as the strength of the upper level winds (jet stream) and if there are any blocking features in place.

Seasons and Seasonality+-
1. Why is it that the equinox has not yet arrived (equal day and night - 12 hours) yet some meteorologists say that we are in spring? I thought that spring by definition was at the equinox!

True, the astronomical spring is defined by the equinox and it is at this time that we receive approximately 12 hours of sunlight. However, when meteorologists and climatologists refer to spring, they are often grouping together the three transition months that lie between the coldest and warmest months of the year. Using this criterion dictates that meteorological/climatological spring is actually defined to be March, April and May.

2. Why does the North Pole have roughly six months of daylight and six months of darkness? Does the same apply to the South Pole?

The reason why the North Pole experiences four to six months of darkness in the winter and four to six months of daylight in the summer is because of the earth's tilt. The earth's vertical axis (the axis on which it spins) is tilted 23.5 degrees. At the same time, the earth also revolves around the sun. It is this combination of tilt and orbit that gives the total darkness or daylight.

When the earth travels around the sun, its tilt causes the North Pole to either point away from the sun (as in winter) or towards the sun (as in summer). When the North Pole is pointed towards the sun in the summer, it is exposed to constant sunlight for a period of months. When the North Pole is pointed away from the sun in the winter there is total darkness. The same goes for the South Pole.

3. What is the "ideal" range of humidity for the inside of the house during the winter months?

Typically during the winter months the relative humidity in a home runs at around 15%. This is too low because it causes your skin to chap and your throat to feel dry. It is suggested that the relative humidity in your home should be kept between 35% to 45%. By keeping the humidity up in your home, you won't need to have the thermostat set as high because less moisture will be evaporating from your skin, causing you to feel more comfortable.

4. What is a "normal" temperature?

A normal of temperature, precipitation or any other weather element is the average of the observed values of that element over a period of time. The period of time depends on how long the particular weather station has been in service. The word "normal" can be misleading because values other than the "normal" are not unusual.

By international agreement, averages or normals cover a 30-year period from the beginning of one decade to the end of the third, e.g., from 1971 to 2000. For example, to calculate the normal daytime high temperature for Winnipeg on September 15, add together the daily high temperatures on this day for the 30 years from 1971 to 2000 and divide the total by 30. This quotient is the average or normal daytime high temperature for September 15 from 1971 to 2000 inclusive. Normals give a general idea of what conditions might be expected on that date.

5. If "normal" temperatures are calculated as a 30-year average, how is it possible to have jumps between daily normals?

In Canada, we calculate the daily normal high using the recorded daily high for the past 30 years. The high of the day before or the day after is not considered in the calculation. Through this averaging, extreme values will be included in the data set. Therefore, a day to day variation in the "normal" temperatures will occur.

In the United States, the climatic normals are calculated differently. The high temperatures for each month are run through a statistical algorithm and the extremes are removed. After the variations are removed, the 30-year normal values are calculated. Thus, the result is a gradual change in normal values with no significant jumps.

6. How is sunrise and sunset determined?

The sunrise and sunset is calculated based on a smooth Earth (no mountains). The measurement of sunrise is taken the moment the top of the sun breaks the horizon while the measurement of sunset is taken the moment the top of the sun dips below the horizon. Additional information is available from the U.S. Naval Meteorology and Oceanography Command website.

7. How do I find today's sunrise and sunset times for Canadian cities?

Sunrise and sunset times are shown on your city's 7 Day forecast page, immediately below the current weather observations (large weather icon and temperatures at the top of the page).

8. When did the Farmer's Almanac first appear?

Throughout the centuries, almanacs have been an information source on the movements of planets and stars, the phases of the moon, dates of eclipses, and precise times of sunrise and sunset and high tides for every day of the year. The first almanacs date back over 2000 years to the Middle East. A Canadian almanac first appeared in the 1850s.

Almanacs are most noted for their weather predictions – not often better than climatology (the average weather for a specific day based on history).

Regional and Extreme Weather+-
1. Where is the hottest place in the world?

The location with the highest temperature ever recorded belongs to Al 'Aziziyah, Libya in the northern Sahara, when on September 13, 1922, the temperature in the shade reached a scorching 58°C. This beat the previous record of 57°C, observed in Death Valley, California at Furnace Creek (also known as Greenland Ranch).

2. Where are the hottest places in Canada?

The hottest places in Canada are the dry interior valleys of British Columbia (Thompson, Okanagan, and Fraser Valleys). In summer, the average daily high temperature exceeds 28°C at Lytton and Osoyoos, B.C. The highest temperature recorded in Canada is 45°C at Midale and Yellow Grass, Saskatchewan. This happened on July 5, 1937.

3. Where is the wettest place in the world?

Mount Waialeale on the island of Kauai in Hawaii is known as one of the wettest places on earth, receiving rain an average of 335 days a year.

When the amount of rainfall is considered, locations in eastern India could be considered the wettest in the world. For example, Cherrapunji, in northeastern India, receives about 10,820 mm annually - that's 11 metres of rain. In one year, last century, it received a colossal rainfall over 2 times the average, making it the wettest single year in world history. Most of its rainfall occurs in the monsoon months of June, July and August.

In Canada, Henderson Lake on Vancouver Island is considered the wettest region, with an average annual rainfall of 6655 mm. That's about half the annual rainfall of the world's wettest locations.

4. Which province is the wettest?

The province with the wettest individual locations is British Columbia. Some areas on Vancouver Island and the mainland coast receive more than 3000 mm of precipitation per year. However, some of the southern interior valleys (the Okanagan, for example) receive less than 400 mm annually, making them among the drier locations in Canada.

The province with the most precipitation spread over its entire area is Nova Scotia, receiving between 1200 mm and 1600 mm of precipitation per year.

5. Has it ever snowed in Los Angeles, or in any of California’s major cities?

In downtown Los Angeles, snowflakes have been observed on over 20 occasions in the past 100 years. However, on January 15, 1932 more than 5 cm of snow fell during the morning in the downtown, the most ever recorded on one day in Los Angeles. Even the beaches at Santa Monica were white with snow. San Diego received a centimetre of snow that remained on the ground for a little more than an hour. San Francisco's most memorable snowfall came on February 5, 1887 when snowfall blanketed the city with 10 cm. In these areas, snow is most likely to fall along the coast when a strong northeasterly flow of cold air descends from the mountains.

The snowiest place in North America is the Cascade Mountain range in Washington State where over 1500 cm of snow falls on average every year. Canada’s snowiest location is Glacier National Park in British Columbia where nearly 1500 cm of snow falls annually.

6. Why is it that on the East Coast they get hit with heavy snow and cold and the West Coast gets warmer weather in the winter when they appear to both be on the same latitude line and near the ocean?

The prevailing winds in the mid-latitudes of the Northern Hemisphere are generally westerly. This pushes air masses and weather systems from west to east across Canada. For eastern Canada, this means cold air masses travel eastward over the continent and occasionally meet with moisture-laden low pressure systems from the south. On the west coast, the flow is usually off the warm Pacific Ocean. The ocean keeps the air masses relatively mild.

7. Why is the weather in North America, e.g., Ohio, colder than the weather in London, England, even though England is further north from the equator?

The prevailing westerly winds in the mid-latitudes of the Northern Hemisphere are responsible for this difference. Weather systems in England generally come from the Atlantic Ocean which helps to moderate the temperature. On the other hand, the interior of North America is subject to both mild air masses from the Pacific and outbreaks of arctic air which can come directly from the polar regions without being moderated by water.

8. There is lake-effect snow near the Great Lakes, but what about smaller lakes?

There are several conditions required to form lake-effect snow. The most important one is sufficiently cold air moving across a large body of water. For example, the size of Shuswap Lake around Salmon Arm, B.C., is too small for winds to pick up enough moisture to produce significant lake-effect snow like what occurs downwind of the Great Lakes. However, under the right conditions, even small lakes like Lake Simcoe in Ontario can provide enough moisture to produce flurries.

9. Why is Ottawa colder and snowier than Toronto?

The Great Lakes, and specifically Lake Ontario, help to keep Toronto warmer than Ottawa during the winter months. Ottawa has a lower average temperature which allows for greater snowfall as more of the total precipitation falls as snow rather than rain. Ottawa also experiences more total precipitation during the winter because of its closer proximity to large nor’easter storm systems which develop along the eastern seaboard of North America.

10. Why do areas like Mansfield, Ontario, not receive the snowstorms that towns five and ten minutes west and north of it receive?

It is difficult to generalize the statement and say that any one location is significantly warmer, colder or receives less precipitation than a nearby location without looking at recorded meteorological information. For comparisons, local weather stations must be close enough together to detect differences between locations that are geographically close.

Meteorologists often use the term ‘local effects’ to describe large differences in weather over relatively small areas. The location of lake-effect snow bands is one example of a local effect.

11. From which direction do winter storms generally come from in the city of Ottawa? Has there been a change in the severity of storms in the Ottawa region?

In general, weather systems move from west to east in Canada, and most winter storms moving in to Ottawa come in from the west. There can be variations in this direction. Some weather systems may move in from the southwest, and some from the northwest. Generally, the storms with the heaviest precipitation tend to come from the southwest because they draw on warmer air with more available moisture. In general, the "average severity" of storms in this area has not changed significantly over the past few decades. Of course, some winter storms leave more snow than others and records of all kinds are occasionally set, but there has been no significant trend observed in storm severity.

12. Why is it that southwestern British Columbia never gets caught in a deep freeze or a cold snap the way the Prairies do in the winter?

Coastal British Columbia rarely experiences a deep freeze for long periods of time because the average wind flow for B.C. during the winter is from the west. This wind direction provides a mild flow of Pacific Ocean air over British Columbia. However, even coastal B.C. can occasionally experience cold temperatures when an arctic high pressure system pumps cold air through the interior valleys and out to the coast. In these cases, the wind blows from land and subfreezing conditions can occur across the Lower Mainland. However, these episodes of cold air rarely last for longer than ten days as the westerly flow from the Pacific eventually returns.

13. Vancouver, British Columbia once had a cyclone about fifty years ago. Can we expect any high winds - ever - like are seen in Florida? Is it true that hurricanes happen on the east coast and cyclones on the west coast?

The coast of British Columbia experiences very strong low-pressure systems that can bring hurricane force winds (greater than 120 km/h). However, because of cool Pacific Ocean waters, the west coast of Canada does not experience tropical cyclones so it is impossible to achieve the extremely high wind speeds generated by a major hurricane. Occasionally, the remnants of a typhoon can cross the Pacific and affect the west coast as an unusually powerful low pressure system. Hurricanes do occur along the west coast of North America, along the Mexican coast where water temperatures are warm enough to support tropical cyclones.

14. Why is it often very windy in the Prairies?

The main reason is topography. The Prairies’ flat terrain allows air to blow across the region without any obstacles like mountains, forests, valleys or hills. Without as much friction to slow the flow of air, conditions are generally windier than in other parts of the country.

15. Why are the summer prevailing winds in Winnipeg from the west but 200 km away in Kenora the winds come from the south?

Both Winnipeg and Kenora have average prevailing winds from the west to southwest direction when 12 months of wind direction observations are averaged together. This "average direction" is typically referred to as a "Wind Rose" analysis. Wind Rose analyses are used to design airport runways and layouts.

16. What is the standard sea level barometric pressure for Vancouver, B.C.?

Standard sea level pressure is the same everywhere. It is 101.325 kPa or 1013.25 millibars.

17. Why do weather patterns in the U.S.A. usually travel from west to east?

Weather patterns in the U.S.A. (and Canada, too) usually travel from west to east because the prevailing winds in the atmosphere in the middle latitudes blow from west to east. These winds transport areas of high- and low-pressure, which cause the weather.

18. Where in Canada are thunderstorms more likely to be and what makes these areas different from others that don't get as many thunderstorms?

Two areas of Canada experience significantly more thunderstorm activity than the rest of the country: Southern Ontario and the foothills of Alberta followed closely by southern Manitoba and Saskatchewan. For a thunderstorm to occur, instability is required. Instability occurs when warm humid air at the surface lies beneath cooler, drier air higher in the atmosphere. Southern Ontario receives its warm humid air from the Gulf of Mexico. Thunderstorms most often occur here in the summertime when southwest winds bring the humid air mass into the region.

In contrast, westerly winds in the upper atmosphere ensure cool dry air is aloft over Alberta. This creates the necessary instability for thunderstorms to form. Additionally, the foothills act as a trigger for thunderstorm development as air is forced to rise in their vicinity. The southern Prairies, especially southeast Saskatchewan and southern Manitoba, are a close second for thunderstorm activity as warm humid air from the U.S. fuels thunderstorm development.

19. In Ottawa, as soon as November 1 comes around every year, there are soft grey clouds that hang over the city for the whole month. Is there a lot less sun this time of year and what would cause these grey clouds to linger day after day?

The hours of bright sunshine are low during November as the air continues to cool and the relative humidity increases. Low clouds can be stubborn to clear since heating from the sun is insufficient to mix the air and dissipate the clouds. Sunshine hours increase in the mid to late winter when colder but drier arctic air replaces the cold moist air of late fall and early winter.

20. Is it true that Oklahoma has the greatest occurrence of tornadoes of any U.S. state or Canadian province?

Oklahoma is part of the area known as "Tornado Alley" which has the highest documented occurrence of tornadoes in the world. The parts of Canada which have the highest tornado occurrences are southern Ontario, parts of Alberta, southeast Saskatchewan and southern Manitoba.

21. Why are there no hurricanes in California?

The eastern North Pacific Ocean off Mexico and Central America is the second most active hurricane alley with nearly one quarter of the world's tropical storms. In a typical year, 17 tropical storms form there, compared to nine or ten in the Atlantic and Caribbean.

Despite all this storm activity, hurricanes rarely make it to the California coast for two reasons:

  • Tropical cyclones moving out of the tropics tend to move toward the west-northwest. In the Atlantic, this direction often brings storms toward the United States. In the Eastern Pacific, a west-northwest track takes hurricanes away from the California coast. 
  • Water temperature: Along the Atlantic coast, the Gulf Stream provides deep warm water above 27°C to fuel hurricanes. Water currents off southern California are normally too cold to sustain tropical storms.

Any hurricane that does make it close to California usually fades quickly over the relatively cool waters, although its remains occasionally bring the region strong winds and flooding rains.

22. Why do space flights get cancelled because of weather when they fly above any weather systems?

Space shuttles are more vulnerable to weather than an ordinary airplane. A simple thunderstorm, a few drops of rain, some clouds, or strong winds can delay or cancel a shuttle launch. This is because of the fragile components used on the space shuttle.

When it is time to fuel the main engines, the combination of humidity and temperature can create ice on the tanks. Chunks of ice could fly off and damage the shuttles' insulating tiles at blastoff. Rain could soak the tiles. Later they could freeze in space and crack. Surface winds, above 45 km/h, could blow the shuttle into the access tower during liftoff.

Cape Canaveral is located in one of the most active thunderstorm regions in the world, with an average of 100 thunderstorms a year. On November 14, 1969, lightning struck Apollo 12 half a minute after liftoff. Weather was also to blame, in part, for the explosion of the space shuttle Challenger – on the night of January 28, 1986, freezing temperatures may have affected the rubber seals in the booster rockets.

Other Weather FAQs+-
1. How is the water content of snow measured?

As a very general rule, the depth of freshly fallen snow is converted to its water equivalent by dividing that depth by 10. However, the water content of snow varies greatly , depending on the temperature, wind speed and moisture content of the air through which the snow falls. Very wet snow falling in air near freezing may have a water equivalent of 6:1, meaning 6 cm of snow = 1 cm of water. On the other hand, with dry and powdery snow the ratio may be as high as 30:1. The only sure way to measure the water content of fresh snow is to melt it. The standard instrument to measure water equivalent is the Nipher snow gauge. The snow in this receptacle is taken indoors until it completely melts. The contents are measured to get the true water content of snow since the last observation.

2. How is snow measured?

Snowfall measurements just may be the least precise of all weather observations. In most countries, snowfall measurements are no more complicated than simply going out and sticking an ordinary ruler into the snow in several places and taking an average depth. Getting a measurement that is truly accurate, however, is rarely that easy. Finding a representative site can be a problem. The best place to take measurements is in an undisturbed, flat, open area away from overhangs. The standard snow ruler is one metre long and marked in centimetres by fifths. Anything less than 0.2 cm is noted as a trace. It is important to note that the following things happen to snow as it sits waiting to be measured:

  • If it's warm, snow melts as it hits the ground 
  • If it's windy, snow drifts or blows away 
  • If it accumulates over 10 to 15 cm, snow settles and compacts under its own weight and evaporates

Because of these fates, snow depth on the ground sometimes decreases even as snow continues to fall.

3. Why kilopascals and not millibars?

In 1971, Parliament adopted the modern form of the metric system known as the International System of Units or SI. That same year, the international body responsible for maintaining standards of measurement decided to replace the "bar" as in millibars, with the Pascal as the SI unit of pressure. Millibar is metric but not SI metric. The SI metric system is founded on seven well-defined base units including the metre for length, kilogram for mass and second for time. A second group contains units that are derived directly from the base units. For example, pascals derive from kilograms, area in square metres and time in seconds. The derived unit of pressure, pascal (Pa), is named in honour of Blaise Pascal, a 17th century French physicist and writer. Most home barometers measure air pressure in inches or millimetres of mercury or in units called millibars. All official pressure readings, though, are expressed in kPa. If your barometer has units in inches, to convert to kilopascals multiply your barometer's readings by 3.386. For example, if your barometer is reading 29.91 inches, that's 101.31 kPa.

4. What is the relationship between the various terms used in measuring atmospheric pressure: inches of mercury, kilopascals, millibars and inches. Why can't they be correlated in the reporting of weather conditions?

All the above relationships are just a different way of measuring a height of mercury column in a mercury barometer. Different measurements show equivalents in different measurement systems: Imperial (inches of mercury, pounds per square foot), metric (millimetres of mercury) and International Scientific (SI) units (millibars, kilopascal).

1013 millibars = 101.3 kilopascals =29.92 inches of mercury.

5. How do you set a barometer?

A barometer is usually corrected to sea- level pressure. This is done by knowing that, on average, atmospheric pressure decreases by about 1 kilopascal (kPa) for every 100 metreers’ increase in elevation. To convert from station pressure to sea level pressure, add 1 kPa for every 100 m that the station is located above sea level. For example, if the station pressure at Ottawa International Airport (elevation 114 m above sea level) is 100.05 kPa, add 1.14 kPa to find the sea- level pressure. The sea level pressure would be 101.19 kPa.

6. Is the air pressure shown in the local forecasts a corrected figure or uncorrected? How do you convert one to the other?

The pressure on thein local forecasts is corrected to reflect the sea- level pressure. It's a little complicated. If you have a barometer at home, you will notice your barometer will actually read at a lower pressure than what you will see on the television screen.

Take Vancouver and Calgary for example. Vancouver is about 3 metres above sea level and Calgary is about 1000 metres above sea level. The pressure in Calgary is lower than it would be in Vancouver because the weight of the air above any given place in Calgary is less.

Here's how you convert air pressure:

P (sea level) = P (observed) + [{(1kPa/100m) x height above sea level]}. For example, if observed pressure is 90 kPa in Calgary, its pressure at sea level is as follows:

P (sea level) = 90 + (1000/100)
P (sea level) = 90 + 10 = 100 kPa.

Why make the conversion? We want to convert everyone to sea level so we can more easily track changes in low and high pressure systems across the country.

7. Where should I place a thermometer?

Where you place your thermometer all depends on its type.

1)Outside thermometers should be placed away from any heat source. For example, heat transfer or radiation may affect a thermometer that is attached to the side of a house. If possible, place your thermometer away from any heat sources (buildings, houses, parking areas and streets) and away from direct sunlight.

2)Indoor thermometers follow the same basic rules. Keep it away from direct sunlight and away from heat sources such as heaters or household appliances. If the thermometer is dual purpose, the sensors for indoor and outdoor use should follow the same rule of thumbthumb as mentioned earlier.

8. When meteorologists report that 30 mm of rain has fallen, it always seems like more. How is rain measured?

Rain is measured with two types of gauges, both having different surface areas. One has a surface area the size of a coffee tin or around a 30 square centimetre opening. This is the worldwide standard rain gauge. The other type is a little larger with a 120 square centimetre opening, and it's called a tipping rain gauge. 30 mm of rain on these types of rain gauges does not sound as impressive as over a larger area, for example, a square kilometre with 30 mm of rain equals many thousands of tonnes of water.

9. I would like to know how the cloud ceiling is measured. For example, if the ceiling is 2,000 feet, how was that determined?

Cloud ceilings are measured with an instrument called a Laser Ceilometer. This large oil- drum- shaped instrument has a laser inside that fires a laser beam up into the sky. As the laser hits the cloud ceiling, it bounces back to the instrument. The time difference between the laser firing and the laser light bouncing back is what we use to calculate the height of the cloud ceiling.

Previously, we used small weather balloons. The weather balloon would be released and we would watch it until it disappeared into the clouds while timing how long it took for the balloon to disappear. Knowing the ascent rate of the balloon, we calculated the height of the ceiling. This balloon method is still used at some stations that are not equipped with a laser ceilometer.

10. How is the dew point temperature measured?

The dew point temperature can be measured with a device called a wet-dry bulb thermometer. A wet-dry bulb thermometer is basically two thermometers placed side by side. The bulb of one is covered by a wick that is always kept wet (wet bulb) and the other is left alone (dry bulb). Just like water evaporating from a person's body right after they come out of the shower, the thermometer with the wet wick will cool as the water evaporates from the wick. The less water vapour in the air or the drier the more water will evaporate from the wet wick. The more water evaporates, the cooler the reading on the wet bulb thermometer. The dry bulb, or regular thermometer, is used as a reference to give the current air temperature. The temperature difference between the two thermometers tells us how much moisture is in the air:- the greater the difference, the drier the air.

For example, a dry bulb temperature of 22°C and a wet bulb temperature of 10°C result in a difference of 12 C°. In this case, the air would be considered fairly dry. A dry bulb temperature of 22°C and a wet bulb temperature of 20°C results in a difference of only 2 °C. In this case, the air would be considered moist.

Electronic hygrometers are used in most modern weather stations equipment to measure the dew point temperature.

11. What is the purpose of having a dew point in the winter? If the temperature reached the dew point and it was still below, what happens?

The purpose of having a dew point in the winter is the same as it is in the summer. We want to see how much moisture is in the air, even in the winter. If the spread between the dew point and the temperature is small, then the air is moist; if the spread is large, the air is dry. The more moisture the air has, the greater the risk of fog, rain or snow.

12. Why does the weather change?

The sun heats different parts of the earth at different rates. Without weather, the warm areas would keep getting warmer and the cold areas would keep getting colder. Weather and weather changes are nature’s way of taking care of this imbalance. For example, when a sunny stretch of weather is broken up by a rainy day brought on by low pressure, that low pressure system was necessary to transport warm air northward toward the cold polar regions and cold air southward toward the warm tropical regions.

13. How do meteorologists determine the number of lightning strikes during a thunderstorm?

Meteorologists can determine the number of lightning strikes during a thunderstorm using information from lightning detection networks. The Weather Network operates its own lightning detection network in Canada, using information from dozens of lightning sensors across Canada and the northern United States. These sensors can accurately detect lightning strikes to within 250 metres and are capable of detecting more than 95% of all lightning strikes. The Weather Network’s lightning detection network can identify cloud to cloud lightning (which suggests a developing thunderstorm) and cloud to ground lightning (which is important for personal safety, property damage and the ignition of forest fires).

14. Does Canada use weather balloons?

Yes, Canada uses weather balloons or, as they’re called, "radiosondes." A radiosonde is the instrument attached to the balloon. Radiosondes send back measurements of temperature, humidity, pressure and wind as the balloon rises. Environment Canada operates 31 stations in Canada where radiosondes are launched twice a day, once in the early morning and then again in the evening.

15. Where can I find out about wind chill?

For information about the wind chill in Canada, including the formula and cold weather ailments and safety tips, visit wind chill in's Glossary.

16. When is the first day of fall, winter, spring and summer?

The first day of the astronomical beginning of these seasons is generally the 21st, give or take one or two days, of September, December, March, and June. However, in reality the weather typically associated with these seasons usually begins a few weeks earlier.

You may find more information about the seasons by visiting the Sun/Moon/Season Calculator on

17. Why is the ceiling reported in feet, not metres?

Ceiling is a measurement primarily used by the aviation industry. The standard for the aviation industry is to report ceiling in feet.

Weather Phenomena+-
1. What causes steam to rise from a wet asphalt surface?

Sometimes you can see steam rising from asphalt surfaces when the sun comes out after a rain or a snowfall. The asphalt absorbs the sun's heat and causes the top layers of the asphalt to warm. This in turn warms the moist air in close contact with the road surface. As the rising air currents of warm, moist air above the asphalt encounter the cooler surrounding air, some of the water vapour condenses into tiny droplets that we see as wispy streamers that resemble smoke. Eventually, the rising tufts of steam encounter drier air and disappear.

2. What causes small waterspouts?

Fair- weather waterspouts are formed on warm sunny days, when there is unstable air above athe lake and a slight breeze above the land. As the air warms and rises, air flows in from all directions to fill the slightly lowered pressure formed over that spot. Rapidly rising air is not enough to initiate a waterspout. Topography and local breezes from the shore to the lake contribute or inhibit the development of these fair- weather mini- waterspouts as well.

3. Is a "whiteout" when a blizzard obscures visibility?

True "whiteouts" occur mostly in the Arctic and Antarctic during the day when light is bounced in all directions between a uniformly overcast sky and snow or ice on the ground. Clean snow and ice reflects nearly 85% of incoming light. Falling snowflakes, suspended fog droplets, or ice particles in the air can add to this reflection. In a true whiteout, neither shadows, nearby objects, landmarks, nor clouds are discernable. All sense of direction, depth perception, and even balance may be lost. Land and sky seem to blend, and the horizon disappears into a white nothingness. Whiteouts cause confusion, tricking pilots into believing down is up and travellers into thinking far is near. Of course, we often refer to "whiteout conditions" when referring to blowing snow within snow squalls, winter storms and blizzards that can reduce visibility to near zero. In these cases, all sense of direction and depth perception can be lost as a result of blowing snow making everything appear white to the observer and creating very dangerous conditions for travel.

4. When can we expect Chinook winds?

Chinook winds are the result of moist weather patterns, originating off the Pacific coast, cooling as they climb the western slopes, and then rapidly warming as they drop down the eastern side of the mountains. A Chinook usually begins with a sudden change in wind direction towards the west or southwest, and a rapid increase in wind speed. They generally occur from the fall through spring.

5. Why do I never hear thunder during the winter?

The development of thunderstorms depends largely on how quickly the temperature decreases as you go up in atmosphere. Because surface temperatures in the summer are much warmer than in the winter, there is usually a greater difference in temperatures at the surface than higher in the atmosphere in the summer. When this similar vertical temperature profile develops in the winter, thunderstorms can develop.

6. Why does the sky on the horizon turn red or pink in the evenings?

As the sun begins to set at the end of the day, the sun's rays which reach our eyes must pass through a thicker layer of the atmosphere than when sun is directly overhead. When this happens, molecules in the earth's atmosphere absorb more of the radiation, but it gets absorbed preferentially. The shorter light waves of the visible light spectrum, the greens and blues, get absorbed, while the longer red rays are able to penetrate. Therefore, red is the colour we see. Dust and smoke particles can help to enhance the scattering of sunlight creating even more vivid red skies at dusk.

7. Why is the sky blue?

White light is composed of a spectrum of colours. Molecules of oxygen and nitrogen gas in the atmosphere scatter light, but not all sunlight is scattered equally. It turns out shorter wavelengths of light, such as violet, blue and green, are scattered more by these molecules than longer wavelengths of light such as yellow, orange and red. As a result of this preferential scattering of the short wavelengths of visible light, the sky appears blue.

8. Why the jet stream usually shown as extending throughout all of North America on weather maps, even though most of the time no fronts are depicted in the area?

In weather forecasting, the jet stream is one of the principalle features we use to describe the overall weather pattern. When we talk about the jet stream, we are generally describing the zone of fastest- moving winds in the upper part of the troposphere (the layer of the atmosphere where weather occurs) which define the path storm systems travel and reflect the general division between warm and cold air. The height of the jet stream varies depending on the season and weather pattern, with an altitude of 10 km being a rough guideline for the altitude of the jet stream over Canada.

While the jet stream is typically drawn as one curvy line on a weather map, there can actually be multiple segments of strong upper level winds and even significant breaks where upper level winds are weak. For presentation purposes, the jet stream drawn on weather maps is a simplified version of the often complex structure of the upper level wind fields.

Meteorologists also talk about low-level jets where are separate phenomena. These low-level jets exist within the first couple kilometers of the troposphere, sometimes ahead of strong cold fronts. Like upper-level jets, these low-level jets are the result of differences in temperature and pressure, but they occur on a much smaller scale as part of individual weather systems.

9. We always see the jet stream for North America. What does it look like for the other side of the world, i.e. Europe or Asia?— Is there a jet stream in the southern hemisphere?

Yes. The shape of the jet stream can be thought of as a long, constantly undulating skipping rope which extends around the mid-latitudes of the world. In the northern hemisphere, the jet stream extends across North America, over the Atlantic, through Europe and Asia, and back across the Pacific in a series of ups and downs which meteorologists call ridges and troughs. A similar pattern exists around the mid-latitudes of the southern hemisphere. In both cases, air generally moves from west to east within the jet stream flow, but dips north and south at times depending on the specific weather pattern. It is the constant movement of these ridges (fair, generally warm weather) and troughs (cool, generally unsettled weather) which causes the variation in our weather.

10. What are/is the best times and ideal viewing conditions for the northern lights?

The northern lights, also called aurora borealis, are a result of the solar wind (energetic particles from the sun) interacting with nitrogen and oxygen atoms in the earth’s upper atmosphere, generally above 80 km altitude. The earth’s magnetic field concentrates this interaction in a ring around the north and south magnetic poles. In Canada, this means the northern lights are most likely to be seen in a belt close to 60 degrees north latitude. Many winter nights are clear and free of haze and that is why winter is often suggested at the best viewing time, although there is a tendency for the most auroral activity to occur around the equinoxes.

11. What is the odd blue ring around the moon at night?

The bluish ring around the moon at night is caused by ice crystals high up in the atmosphere (about 7 km or 22,000 feet above the surface) which refract the moonlight in such a way that they create a halo. The effect is much like that which occurs when sunlight passes through an area of rain and creates a rainbow, or when a light passes through a prism and is split into the colours of the spectrum.

The bluish ring is caused by ice crystals high up in the atmosphere (around 7 km above the ground) which refract the moonlight in such a way that they create a halo. A halo sometimes precedes the onset of unsettled weather within the next 24 hours. This is because the ice crystals are part of cirrus clouds, which are those thin, high clouds that often run ahead of an approaching storm system.

12. What does a cross, similar to rings around the moon, mean?

It is probably caused by parts of a halo breaking up. Halos are produced by the refraction of light through ice crystals. A solid deck of high cirrostratus clouds is necessary to obtain a complete halo. If there are breaks, you will see some arcs of the halo. Chances are that when you looked up, there happened to be some breaks at just the right spot for you to see a cross. A halo indicates a possible weather change because high clouds are usually the first to make an appearance from approaching storms.

13. Does lightning come down from the sky or up from the ground to the sky?

Lightning actually does both.

In the typical downward lightning case, an invisible stream of ionized air from the cloud, called a stepped leader, travels downward following a jagged path and will try to combine with a ground streamer going upwards towards the cloud. Generally, there are a few of these upward streamers, and when the first one connects with the main downward stepped leader, there is a massive release of energy called the return stroke. It is this return stroke that we see in the form of the lightning flash and hear it in the form of thunder. All of this happens so quickly that our eyes are only able to see the high energy return stroke. Rarer, is the occurrence of upward lightning that is initiated by tall buildings. These cases work in ways similar to downward lightning except the stepped leader is initiated by the top of a tall building or tower which carries a significant charge relative to the cloud above. If the stepped leader connects with an area of opposite charge in the cloud, upward lightning occurs.

14. What causes sheet lightning as opposed to fork lightning?

Lightning is the result of a massive discharge of energy within clouds or between a cloud and the ground. When this discharge (or giant spark) occurs between the cloud and the ground, we refer to this as cloud-to-ground lightning. Some people call this fork lightning when the lightning channel has multiple points of contact to the ground. When a lightning discharge occurs within a cloud, the light is reflected off the water droplets within a cloud causing a diffusion of the light. At night, this diffusion of light from the original lightning channel causes the whole cloud or much of the sky to light up, creating the effect of a sheet of lightning.

15. How do we predict tides and their height?

Tides are caused by the influence of the moon and sun on the earth's surface in combination with the rotation of the earth. The moon accounts for the majority of the tidal effect with the sun playing a secondary role. The tidal cycle consists of approximately two high tides and two low tides in a day. For example, there is approximately 12.5 hours between high tides. This means that about 6.25 hours after a high tide, there is a low tide.

The moon's distance from the earth is one factor that affects the tides. The tides are highest and lowest (have their greatest range) when the moon is nearest the earth in its orbit. The tides have their smallest range when the moon is farthest from the earth in its orbit.

The phases of the moon also have an influence on tides. The tides are highest and lowest when the moon is new or full. At this time, the moon, sun, and earth are aligned and the sun and moon experience their strongest gravitational attraction towards the earth. These tides are called Spring tides although they have nothing to do with the season. The tides have their lowest range when the moon is in first or last quarter. This is because at these phases, the sun, moon, and earth form a right angle and therefore the gravitational attraction is weakest. These tides are known as Neap tides.

Observations from tidal gauges are used to make accurate tidal predictions since the local bathymetry (shape and depth of the ocean bottom) has a great impact on the timing and height of the tide at any given location.

16. What was the "Perfect Storm"?

The so- called “Perfect Storm” is also known as the Halloween Storm of 1991. This storm developed when an unusually strong trough in the jet stream moved off the east coast of the United States and absorbed the remnants of Hurricane Grace. The resulting storm produced strong winds and incredible waves throughout this part of the Atlantic Ocean, affecting large sea vessels and coastal communities.

17. What is the difference between a cyclone and a hurricane?

The word “cyclone” is a generic term for a low- pressure system. Tropical cyclones (which include tropical storms and hurricanes) develop over tropical ocean regions and have no fronts associated with them. These systems have extremely strong winds very close to the centre of the storm. On the other hand, a mid-latitude cyclone, or typical area of low pressure, forms from the clash of warm and cold air masses that occur frequently at Canadian latitudes. These systems tend to have larger but weaker wind fields than tropical cyclones.

18. What are “les suetes” winds?

On the western shores of Nova Scotia's Cape Breton Island, damaging local winds are known as Les Suetes, derived from the French for southeast: sud est. These strong southeasterlies occur in advance of a low pressure system as the air is funneled through gaps in the Cape Breton highlands. When the wind rushes down the side of the highlands, strong gusts develop which have been recorded in excess of 150 km.

Weather Lore+-
1. What is "the calm before the storm"?

The period of time before severe weather affects an area is known as the "calm before the storm". When a thunderstorm approaches, it pulls in huge amounts of warm and moist air at the surface. The surface winds just ahead of the main rising updrafts within a storm are sometimes lulled into a temporary calm as the primary air motion is upward. The air above the surface continues to ascend and the updrafts well above the surface gain incredible speed – sometimes exceeding 100 km/h. Immediately behind these upward motions of wind, called updrafts, you will find heavy rain, hail, lightning and thunder. This causes powerful downward wind gusts, called downdrafts, to hit the ground. Strong gusty winds will occur as a result of the downdrafts. These effects mark the end of the "calm before the storm".

2. Dry cold versus damp cold?

The assumption that dry cold is better than damp cold is largely a myth. Soldiers exposed to severe cold in climate-controlled cold chambers did not find damp cold any more penetrating than dry cold and, if you consider the physics of heat transfer, the differences between the two are negligible. But why then do the majority of Canadians prefer dry cold to damp cold?

One's perception of comfort or discomfort while exposed to cold air depends on several factors but only consideration to weather conditions will be considered here. Cold, dry days usually have sunny skies, high pressure and light winds – weather that is much more psychologically pleasing than overcast skies and shivering wind chill. Therefore, there's good reason to believe that you'll be more comfortable in a dry cold than humid cold, but it's not because of the difference in humidity. All this assumes one is not perspiring, his or her clothes are dry and that it's not raining.

3. What is good fishing weather?

The saying goes, "When the wind is from the east, the fish bite the least." In the Northern Hemisphere, stormy low-pressure systems rotate counterclockwise with the prevailing winds blowing from the east ahead of a storm. With the approach of such storms, fish head to the bottom of the lake or stream, where they are less active and refuse to bite. Anglers love to argue over which weather makes fish bite more or less. It’s believed that:

  • Fish hide on sunny days or when it thunders. 
  • A slight ripple of the water leads to better fishing.

Good fishing occurs with rising pressure, yet it’s said that fish start biting when the barometer starts to fall. There may be a grain of truth to some of these superstitions. Generally, fishermen are some of the best at reading the signs of weather, hoping it will improve their chances. In the end, anglers probably still have no idea why they catch their limit one day and nary a nibble the next.

4. When leaves show their undersides, is it a sign of rain?

Plants and trees respond in a variety of ways to changes in the weather. It has been said that before rain, the leaves of trees curl up and show a great deal of their under surfaces. Here is a possible explanation. Ahead of a local shower or thunderstorm, the air is moister. The damp air softens the leaf stalks and allows them to be more easily lifted by the breeze. This, coupled with the rising currents of heated air ahead of the precipitation, exposes the under-sides of leaves. However, windy conditions in general will cause leaves to show their undersides and there are many cases where windy weather does not bring rain.

5. Is it colder during a full moon?

A full moon on its own does not contribute significantly to temperature. However, overnight temperatures are often colder with a full moon because there are few or no clouds to trap and hold in the day's warmth (like how a blanket works). When the sky is clear after sunset, the day's heat radiates to space, chilling the air near the surface.

6. Can you tell the weather from smoke signals around a chimney?

Weather lore says that when chimney smoke sinks upon the roof and falls to the ground, it signals rain or snow within 24 hours. In such situations, the dirty particulates in smoke absorb the added moisture in advance of the storm. This makes the smoke heavier and is dragged down to the roof. Conversely, in dry, calm weather, a column of hot smoke from a chimney rises straight and will continue to rise as long as it is warmer than the surrounding air. Under persistent high pressure, the air near the ground is usually dry and cool, encouraging a rising plume. Smoke that rises vertically often foretells good weather. However these are only general rules and modern weather forecasting is much more accurate at predicting precipitation than using smoke signals around a chimney.

7. Can you predict weather by sound?

To a certain degree, this seems to be true. We seem to hear distant sounds such as train whistles and ringing church bells better before a storm approaches.

When the sky is overcast and humid (often the conditions that exist before a thunderstorm), sound can travel farther because rising and lowering air currents and strong gusty winds that rapidly break up sounds are weaker. During fair weather, these movements are present and therefore do not allow sound to travel as far.

There's even a piece of weather lore that supports this notion:

Sound travelling far and wide A stormy day will betide.

8. Why does the wind make more noise in the winter than in the summer?

On average, the wind is 25% stronger in the winter than in summer because of stronger areas of low and high pressure. Part of the reason may simply be that in winter, winds whistle through gaps and cracks around closed doors, windows and open chimneys.

Also, winter sounds are generally much easier to hear because there are fewer competing noises like voices and sounds from birds and insects. Further, wind sounds are more audible as they rustle dry leaves. Actually, the wind can create a whole symphony of noises, including humming telephone wires and whispering pine needles. As the wind rushes by a wire, bare twigs and even the branches of trees, the air becomes unstable and forms tiny whirls or ripples. These vibrations have a pitch that varies directly as the speed of the wind. It is also well known that the humming of telephone wires is loudest when the wires are tightly stretched as they often are during cold weather.

9. If it is red sky at sunset, does this mean that the next day is going to be an excellent day?

The logic behind "red sky at morning, sailors take warning; red sky at night, sailors delight" is that if the sky is red in the morning, any clouds would be to the west, which is the direction from which clouds usually come from in Canada. Conversely, if the sky is red at night (dusk) the clouds would have departed. The red tinge to the sky suggests dry air and the presence of particles that help to preferentially scatter red light towards us. If the dry air is to the east, wet weather may be on the way whereas if the dry air is toward the west, this would indicate fair weather is on the way.

But there are many times when this saying does not hold true. For example, some summer nights can feature a red sky in the evening, only to be followed by overnight thunderstorms. Conversely, a red sky in the morning could occur during the midst of a multi-day dry spell with no rain in sight.

10. What does it mean when you see a rainbow in the sky early in the morning?

There is a rhyme, "rainbow in the morning, sailors take warning." Sailors made observations of weather patterns and they noticed that when they saw a rainbow in the early morning, rain was on its way (or very close to happening). A rainbow is formed when light is refracted through water droplets from moisture in the air, which usually means that it is about to rain or that a storm has just passed.

11. Is there any basis for the belief that a ring around the moon at night means a storm the next day?

The presence of a ring around the moon indicates that there are ice crystals high in the atmosphere. These crystals are the main components of high-level cirrus clouds, which are often the first clouds to appear when a warm front approaches a given area. Typically, a warm front will be associated with a low pressure system which is commonly referred to as a storm. However, sometimes the low pressure system is not close enough or strong enough to produce precipitation the next day.

12. Why "if there is dew on the grass, no rain comes to pass?"

When dew or frost forms on the ground, it indicates that there are calm winds and clear skies during the night. This is characteristic of strong high-pressure systems which generally will bring sunny skies later in the day and no rain or snow. With no cloud cover overnight the surface of the earth is able to cool close enough to its dew point temperature so that water will be able to condense in the form of dew.

About The Weather Network and Meteorology +-
1. Who owns The Weather Network?

Pelmorex Communications Inc. is the parent company that owns and operates The Weather Network and its sister station, MétéoMédia. Both The Weather Network and MétéoMédia are Canada's only 24-hour English and French specialty channels devoted to Canadians' favourite topic of conversations - the weather. At Pelmorex, we are as passionate about the weather as many Canadians are - and then some! It defines all that we do.

Our vision is to be Canada's leading provider of multimedia weather information. And Pelmorex has dedicated itself to making The Weather Network and MétéoMédia a Canadian success story.

The result is that The Weather Network and MétéoMédia, and their respective web sites and MétéoMé are services that Canadians are turning to first when they want current, accurate and detailed weather information to help plan their activities.

Some other facts about Pelmorex:

  • A privately owned Canadian company. 
  • Founded in 1989 by President and CEO Pierre L. Morrissette. 
  • Headquartered in Oakville, Ontario, with broadcast centres in both Oakville and Montreal and regional bureaus in Vancouver and Moncton. 
  • Employs a dedicated staff of more than 275 people across Canada, including the largest meteorological staff amongst all private sector companies in our country.
2. I would like to advertise on The Weather Network television service or web site. Who should I contact?

For advertising information, please contact:
Paula Presley
Senior Vice President, Global Advertising Sales
Phone : 905-829-1159
E-mail :

3. I am a member of the media, who should I contact?

Members of the media, please contact:
Rachel Douglas
Corporate Communications Specialist
Phone : 905-829-1159
E-mail :

4. Where can I find out about career opportunities at The Weather Network?

If you are looking for a challenging career in a progressive, multi-technological company and you feel you've got what it takes, The Weather Network would like to hear from you! We are an equal opportunity employer and we take pride in our diverse workforce. Visit our Career section for more information on our latest job openings.

5. Is The Weather Network hiring professional meteorologists?

At The Weather Network, we are very proud to be the largest private sector employer of meteorologists in Canada. And we're always looking to speak to qualified candidates who want to join our team. If someone says, "Nice day" and you tell them why, then we would like to hear from you! Visit our Career section for more information on joining The Weather Network's team of professional meteorologists.

6. Do you offer meteorological internships?

At The Weather Network, internships are available for meteorology and atmospheric science graduates or students who are working towards a diploma in these fields. These full-time positions run from May to August each year and provide valuable hands-on, operational experience for meteorologists entering the field. To apply, send a resume and cover letter to Human Resources at The Weather Network.

7. How can I reach your Human Resources department?

Human Resources, The Weather Network
2655 Bristol Circle
Oakville, ON L6H 7W1
Telephone : (905) 829-1159
Fax : (905) 829-5800
E-mail :

8. How do I become an on-air presenter at The Weather Network?

Becoming an on-air presenter at The Weather Network requires a unique combination of skills and abilities including:

  • A solid educational background as a primary prerequisite. For example, completion of a university or college program in radio and television, communications, or journalism. 
  • An in-depth knowledge of meteorology and Canadian geography is also essential. 
  • A keen interest in weather and atmospheric science, which is complimented by The Weather Network's extensive in-house meteorology training. 
  • Other important skills relate to performance and presentation, including voice and communication skills, presence and energy. 
  • A passion for the profession, coupled with the ability to work well under pressure while managing a large amount of detailed information, are also essential.
9. Where can I study meteorology in Canada?

There are several universities across Canada that offer graduate and undergraduate diplomas or certificate programs in meteorology/atmospheric science. They include:

  • Dalhousie University, Nova Scotia 
  • McGill University, Québec 
  • University of Alberta 
  • University of British Columbia 
  • University of Manitoba 
  • York University, Ontario
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