Three signs Canada is steadily marching toward spring weather
Spring might feel like it’s an eternity away as bouts of snowy and chilly weather continue spreading over Canada, but there are growing signs that warmer weather is right around the corner.
A barrage of weekend storms in Atlantic Canada. A rare snowy Christmas in Vancouver. Weeks of persistent frigidity on the Prairies. Toronto’s biggest blizzard in decades. It’s been one memorable winter across the country, and we’re emerging from the deep freeze to find that the first breaths of spring aren’t far off. You don’t have to look very far for signs that warmer weather is just around the corner.
SPRING’S FROGS ARE SINGING AWAY
The thermometer isn’t the only giveaway that the seasons are changing. I live in a small part of central North Carolina, where the song of the spring peeper frog rang out from the woods on February 3 this year—the earliest I’d ever heard those cheerful little critters start peeping away (click play on the video below to have a listen!).
Spring peepers are tiny frogs that inhabit woodland ponds, streams, and rivers across a vast swath of the eastern United States and Canada. The little creatures make a big sound as they search for prospective mates, and their unmistakable high-pitched call is a telltale sign the first breaths of spring are here.
We typically hear spring peepers around March in the southern United States, with the amphibians becoming more active into April and May through eastern Canada. The early arrival of the peeping in my neck of the woods might be a good sign that they’re not far off north of the border.
THE PLANTS ARE WAKING UP FROM THEIR WINTER SLUMBER
There are even more natural signs that we’re in the final stages of a long winter. Bees are starting to buzz around and ladybugs are scurrying around in a mating blitz. The plants are just as eager as we are to shake off winter’s cold and get on with the warmth and sunshine.
Scientists often look to specific types of plants for clues that we’ve rounded the corner from winter to spring. The USA National Phenology Network (USANPN) is an organization that tracks the first leaf and the first bloom across the United States.
The USA National Phenology Network's spring leaf index for February 26, 2022. (USA National Phenology Network/USGS)
The group says that lilacs and honeysuckles are “among the first plants to show their leaves in the spring,” so they’re a perfect indicator for tracking the natural progression of spring each year.
Relying on observations and models that utilize known plant behaviour based on weather conditions, the USANPN maps out the progression of this first leaf and first bloom across the country. Comparing the indices to decadal averages can give us some clue if we’re ahead of schedule or falling behind in the “typical” onset of spring weather.
We’ve already seen the first leaf across much of the southern United States, with a later-than-normal leaf in the southeastern states with an earlier-than-normal leaf appearing in the desert southwest and along the West Coast.
The map above will start filling in fast as we tick through the month of March. The first leaf and first bloom usually reach southern Ontario by the middle of April, pushing into southern Quebec and the southern Prairies by the first week of May. The first leaf and first bloom typically spread across the Maritimes and the rest of the Prairies throughout the month of May.
WE’RE FAR BEYOND THE TEMPERATURE SLUMP
It may feel like an eternity amid the snow and ice and bone-chilling cold, but the march toward spring south of the border is steadily making its way toward Canada.
Snowy weather is still commonplace across the country in March and April. Calgary averages about 21 cm of snow during a typical April, while Ottawa usually records about 11 cm of snow during an average April.
However, the long tail of winter is interrupted by increasingly frequent intrusions of comfortable temperatures.
A sharper temperature gradient between the warming south and the stubbornly cold north will start to push the jet stream farther north across Canada. This will allow low-pressure systems to track farther north, as well, affording more opportunities for warm air to flood over regions like southern Ontario.
Take a look at the average high temperatures for Toronto through the winter and spring months. The city bottoms out around -1.5°C in January, then seasonal temperatures begin a steady, rapid climb as we head through March and April. Freezes become increasingly rare in southern Ontario by the middle of April, with the freezing line steadily pulling north over the following weeks.
Tracking both the last freeze and the last frost is a critical milestone for the kickoff of planting season. Anyone who tends a garden at home knows the risk of sowing tender plants too soon.
A hard freeze, where temperatures fall several degrees below freezing for several hours, can kill a plant and ruin an entire season’s harvest in one night. Even a light layer of frost, which can form with temperatures a few degrees above freezing, can harm or kill sensitive plants.
The average date of the last frost is that key milestone for planters and farmers alike.
Vancouver’s temperate climate makes it Canada’s first major city to see its last frost, with an average last frost of about March 18th. Toronto and Ottawa are next to experience their last frost around the last day of April, followed by the Maritimes in the first half of May and the Prairies following through the end of the month.
These are just averages, after all—the actual last frost and freeze can occur much earlier or much later in the season. Last year, conditions were cold enough that parts of Newfoundland saw measurable snow on June 10th.
We’re not quite done with winter yet, Canada, but there are plenty of signs that we’re on the way to warmer weather and things are looking up in the days and weeks to come.
What does this spring have in store for your town? Check out our spring forecast and get prepared for whatever heads your way over the next couple of months.
Thumbnail courtesy of Unsplash.
