After a particularly cold and snowy winter across much of Canada, it appears summer may tip the scales in the opposite direction.
Environment and Climate Change Canada (ECCC) released its three-month summer forecast which compares outlook probabilities to Canada’s climate from the 30-year period spanning 1990-2020.
The verdict: expect heat and humidity.

Temperatures

Across the whole country there is a high likelihood of temperatures exceeding averages this summer, Environment Canada says. But there will still be some variance depending on where in the country you live.
“The strongest warm signals are found in British Columbia, Yukon, along the mainland portions of the Northwest Territories and Nunavut, the northern parts of the prairies, as well as Atlantic Canada,” Jennifer Smith, a meteorologist with ECC said Friday.
However, she noted the hot weather is a trend, but pockets of cooler air will still make their way across the country.
“Day-to-day weather will continue to be shaped by passing weather systems and local influences like cold fronts, thunderstorms, and onshore breezes near lakes and oceans,” she added.
Some parts of Canada are already experiencing that warmer weather. After a short and unpredictable spring, parts of southern Ontario including Ottawa and Toronto are seeing temperatures in the high 20s pushing 30 C.
According to Peter Quinlan, a meteorologist with Global News, the seasonal high for this time of year in Toronto is 23 C.
“It looks like we’ll be above that mark right through the next week. So we are getting into some heat in southern Ontario,” he said.
“It kind of often goes in a seesaw pattern: when the west cools the east warms and then vice versa,” he added. “But it looks like overall the trend throughout the summer will be warmer than normal.”
Last week, Saskatchewan experienced its first heat event of the season with the average temperature across the entire province sitting at 29 C.
Above-average temperatures are being driven by a number of factors, but the most significant two are climate change and El Niño.

Nathan Gillett, a research scientist with ECCC said average summer temperatures have risen 1.65 C in Canada since 1948.
“Canada is warming at nearly twice the global rate,” he said. “The forecast anomalies are relative to that 1991-to-2020 base period. And what that means is that because of the long-term warming, we’re going to see warm anomalies more often than cold anomalies.”
Climate change also increases the possibility for extreme heat days. An extreme heat event is called when the temperature reaches or exceeds 31 C or the humidex exceeds 40 for two or more days.
This year is also expected to develop a particularly strong El Niño.
El Niño refers to a warming of surface ocean temperatures which typically bring a warmer and drier winter to the Americas.
But Quinlan said the phenomenon appears to be developing earlier this year, which could bring hotter conditions across southern Canada.
Humidity

Environment Canada projections also show an increased likelihood for higher than normal specific humidity, which measures the mass of water vapour in the area. Humidity can make it feel much warmer than it actually is, and can hinder the body’s ability to cool itself down.
Smith said higher humidity will affect nighttime temperatures.
“When it’s very, very muggy, the overnight temperature has a hard time cooling off overnight, which makes it difficult for humans to cool off during the nighttime period,” she said.
Quinlan said one of the biggest concerns this summer is that there may not be as much relief with nighttime temperatures.
“Those nighttime temperatures are really trending upwards,” he said. “So if you don’t have air conditioning you won’t be able to open the windows and get that refreshing of your indoor temperature as easily as you would say in a more typical year or in a below-average year.”
Quinlan said regions closer to bodies of water, namely southern Ontario and Quebec and Atlantic Canada, typically experience higher humidex levels.
Environment Canada modelling shows an anomaly in B.C. The westernmost province usually experiences a drier summer thanks to winds and mountains. But this summer the area can expect more moisture in the air, making it feel sticky.