Updated June 20, 2025 at 10 p.m.
Quebec is about to experience a good heat in the coming days. But despite this beginning of summer marked by a damp and sustained heat, this first true heat wave could well be the strongest of the season.
At the end of spring, a first overview of summer trends announced a hot summer. However, the most recent models are slightly falling down the temperatures. The heat will be present, but less persistent than expected, and the heat dome which is currently installed on the west of the continent should not overflow in Quebec as often as anticipated.
Shy heat, humidity well present
Overall, Quebec should still record temperatures above normal, especially due to sweet nights. However, the heat of the end of June will not set the tone for the rest of summer. A hollow could come back to settle on the east of the continent, limiting the progression of the hot air masses and making the heat more hesitant, especially in July.
Despite everything, we expect an usual number of heat waves, about four, counting that of the next few days. But these episodes could be more spaced and less durable than the large heat waves observed for some years.
What could make summer more uncomfortable is not so much heat as humidity, which should be more marked than normal. Even with more moderate temperatures, heavy and sticky weather may be present.
Stormy and unstable
Abundant humidity, coming from an abnormally hot Mexico Gulf could supply precipitation superior to normal on a good part of Quebec. Although regional forecasts are difficult to refine, the province is expected to find themselves near or above rain, with an increased risk of thunderstorms.
These thunderstorms could be more numerous than the average, which is around 17 days of violent thunderstorms in summer in Quebec. In question: the formation of a “belt of fire” around the heat dome, which will stretch from northern Ontario to Quebec. The difference in marked temperature in this area will promote the frequent emergence of stormy cells.
