Halloween forecast: Will your costume need a winter coat?
Will the scariest part of your Halloween be the forecast this year? See what our verdict is for your part of Canada
Halloween is almost here across Canada!
Before you put the finishing touches on your costume, you might be wondering: Will the weather co-operate?
A tale of two seasons is beginning to take shape, with some Canadians facing an early taste of winter, while others could be enjoying a surprisingly mild trick-or-treat.
The catch: Although we can give you some guidelines for temperature projections, nailing down a three-hour, trick-or-treat window will be futile a week out for those of us on the edge of precipitation chances.
The divide
All three major weather models are showing a similar temperature divide brewing across Canada into the spooky Halloween weekend.
Colder-than-seasonal temperatures are expected across parts of Western Canada, and unusually mild conditions farther east.
Parts of B.C. and Alberta could shiver through temperatures several degrees below seasonal, while the eastern Prairies and Ontario could enjoy temperatures well above what late October normally delivers.
Disclaimer: Above-seasonal doesn’t necessarily mean warm. Remember it’s all relative this time of year, especially when the sun goes down.
British Columbia: A chilly trick-or-treat
Do not dress as a tropical tourist this Halloween. A pocket of below-seasonal air is forecast to swirl across southern B.C.
A weak trough will be draped across the coast, with shower chances increasing as you head north.
Think single digits along the coast, and temperatures falling to near (or below) freezing through the Interior.
Prairies: Dramatic weather contrasts
Alberta will be decidedly chilly this Halloween, with below-seasonal temperatures likely.
Can your Halloween costume accommodate a winter jacket?
Trick-or-treat temperatures will be falling towards the freezing mark here, while milder temperatures could be present across southern Manitoba.
Precipitation odds will increase as you work your way east, but this disturbance may bring showers and some gusty winds
Costume verdict: Bundled-up superheroes across the western Prairies. Maybe a lighter costume farther east, but a jacket or waterproof layer could be the play.
Ontario: Halloween treat?
Parts of Ontario looks drama-free, but there will be a developing disturbance across the Great Lakes basin as we push through the weekend.
A high-pressure bubble along the coast of North America should ward off the worst of the spooky weather, and we have high confidence it’ll be upwards of five degrees above seasonal--and even a bigger anomaly may develop as get closer.
Extreme southwestern Ontario could feature the warmest, trick-or-treating weather in all of Canada.
Costume verdict: Multiple layers may not be needed across southern Ontario, so you can hang up the winter coat, but keep the rain poncho on reserve with a possible trick still looming.
Quebec: A promising pattern
Although Quebec is unlikely to benefit from the warmest air farther southwest, it still looks relatively calm with temperatures within a few degrees of seasonal norms.
Higher confidence for drier weather up and down the St. Lawrence River, thanks to an area of high pressure extending up and down the eastern side of North America.
Costume verdict: Some strategic layering will be necessary, and farther north, winter-tested costumes remain the safer bet for now.
Atlantic Canada: Higher-pressure treat
High confidence of a dry Halloween, but a minor chill will be most likely be in the air with a weak, upper trough near Newfoundland.
Temperature forecast is a little more complicated with competing air masses.
Mid-to-low, single-digit temperatures will be the most likely Halloween trick-or-treat temperature, so some costume layering will be recommended.
Slight chance that the extreme southwestern Maritimes wull verify warmer, so we’ll watch that trend closely.
Costume verdict: A couple of warmer layers below the costume should do the trick. The biggest Halloween surprise could be just how dry it will be.
The overall vibe: Don’t trust the exact forecast too early, but the temperature projections are the most reliable in this time frame. Halloween is going to deliver some uneven weather across Canada this year in typical fall fashion, with a disturbance sandwiched squarely in Central Canada.
Canadian Halloween extremes
Warmest Halloween high: Welland, Ont.: 26.1 C (1876) Shoutout to 2024 when highs across southern Ontario pushed into the low 20s. Ottawa had its warmest Halloween on record (23.9 C)
Coldest Halloween high: These vary across Canada, from barely above freezing in Toronto in 1917, to a high of just -8.3 C in Kapuskasing, Ont., in 1951.
Farther west, it’s been much colder. Trick-or-treating in Churchill, Man., in 1991 would have been extreme, with the daytime high just reaching -14 C. Kindersley also featured a nearly -14 C high in 1984.
The year 1984 continues to be an infamous year when the high in Red Deer didn’t budge above -18.4 C--absolutely exceptional for late October.
Edmonton takes one of the top chill spots with a -18.5 C high in 1984. That year (1984) continues to deliver some of the weirdest weather across British Columbia.
Weirdest Halloween weather: Halloween 1984 actually snowed across the South Coast of British Columbia--across portions of the Lower Mainland and up the coast of Vancouver Island.Snow is pretty rare at any time of the year, but in October, it was unprecedented until 1984.
Nanaimo, B.C., picked up 20 cm of snowfall, while Campbell River, B.C., received nearly 30 cm.
One of the biggest Halloween snowfalls occurred in Banff, Alta., in 1990, when 37.6 cm of snowfall accumulated.