Published on Jul. 1, 2026, 12:24 AM
Updated on Jul. 1, 2026, 9:41 PM
A stiflingly hot Canada Day is in store for Ontario and Quebec, with daytime highs in the 30s and humidex values in the 40s. The heat and humidity are creating the perfect conditions for severe thunderstorms to develop in some areas
The heat is on in southern Ontario and Quebec this week, as are the chances for severe weather.
With daytime highs approaching or surpassing the 30-degree mark, the heat will help to fuel a risk of thunderstorms in Ontario and Quebec again on Wednesday.
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Many folks have outdoor plans for Canada Day, which will feature a threat of thunderstorms in both provinces. Residents should remain weather-aware on Wednesday, be on guard for rapidly changing conditions, and have a plan to take cover if/when severe weather strikes.
Canada Day plans in jeopardy with severe storm potential
The building heat in Ontario and Quebec this week has created an increasingly unstable atmosphere, which will provide plenty of fuel for thunderstorms.
SEE ALSO: Ontario’s first extreme heat event of the summer will invade this week
Widespread heat warnings are still in place, with feels-like values into the 40s Wednesday afternoon across southern and eastern Ontario, including Ottawa and the Greater Toronto Area (GTA), as well as across Quebec and parts of the Maritimes.
Also on Wednesday afternoon, severe thunderstorms are possible near Peterborough and areas east towards Bancroft and Ottawa, and will track towards Lake Erie and the international border.
