With autumn approaching, weather experts say summer-like conditions could linger well into September, and a heat dome south of the border could have an impact on some parts of Canada.
An enormous heat dome is raising temperatures and bringing storms to the southern and central parts of the United States this week. Although the epicentre of the heat dome is south of the border, the unusually warm air also affects Canada, said David Phillips.
“We’re still getting summer-like weather, and some of it could be brought to us by these … high-pressure areas, these heat domes,” Phillips, a senior climatologist with Environment and Climate Change Canada, said in a video interview with CTVNews.ca in Barrie, Ont., on Wednesday.
A heat dome forms when a “persistent high-pressure weather system traps hot air over a region,” according to the Canadian Climate Institute, a policy research organization.
Phillips added that it’s “like putting a lid on top of an area.”
“The air gets squeezed by the high-pressure area coming down, and it gets warmer and drier, and it lasts morning, noon and night, day after day after day,” Phillips said.
Earlier this week, The Weather Network reported that the heat dome will influence conditions for most of Canada’s southern areas.

Canada won’t feel ‘same intensity’ as U.S.: meteorologist
Kelsey McEwen, chief meteorologist and co-host of CTV Your Morning, said the U.S. heat dome won’t have much of an impact on most of Canada.
“The atmosphere behaves really like a fluid ... there’s a really hot parcel of air over the southern U.S.,” McEwen said in a video interview with CTVNews.ca on Thursday. “We may feel the periphery of effect of it in Canada, but it would be for the most southern communities.”
She noted that areas in southwestern Ontario, like the Windsor-Sarnia region, have been warm over the past few days.
She forecasts temperatures to cool down in Ontario heading into the weekend, while the southern Prairies will become hot, which she said may be “loosely connected” to the U.S. heat dome. She explained that the mild temperatures expected Friday and Saturday in southern areas of Saskatchewan and Manitoba are directly due to “an upper ridge, an area of high pressure right over that region.”
“But because we are so much farther north, and that (the) hottest, most humid air is so far south, closer to the Gulf of Mexico, we’re not feeling the same intensity of the heat here,” she added.
‘You can’t escape it’
Heat domes can have dangerous effects, including deaths, Phillips said.
“You can’t escape it. You can’t just say, ‘Oh, I’m just going to go to the beach and get away from it,’” he explained. “It’s covering your whole area … so you’re stuck in it, and you’ve got to endure it for as long as it lasts.”
During this time of year, Phillips said heat domes don’t last as long and tend to be less intense than during July and August, because there are fewer hours of sunshine.
“Climate change can make them more frequent and more intense and lasting longer,” Phillips said.



