Toronto Grow

Ontario is in the grip of an intense heat wave, with temperatures soaring into the high 30s and humidex values reaching the mid-40s. Toronto hit 36°C on Tuesday, matching its hottest day of 2026, while Armstrong, Ont., recorded 40.7°C on Monday—the province's hottest temperature since the historic 1936 heat wave. Several communities, including Atikokan and Thunder Bay, also set new July heat records as the extreme weather continues across the province.

🔥 Heat Alert for Toronto & Southern Ontario

A major heat wave is set to sweep across Toronto and southern Ontario this week, bringing scorching temperatures and dangerous humidity. Daytime highs are expected to remain in the mid-30s, while humidex values could climb into the low to mid-40s, making it feel significantly hotter.

According to The Weather Network, a powerful heat dome that developed over the eastern United States is expanding into the Great Lakes region, fueling an extended stretch of extreme heat through Canada Day.

On Tuesday, Toronto is expected to see heavy thunderstorms in the morning before skies clear and temperatures surge. The forecast calls for a high of 33°C, but with the humidity, it could feel as hot as 43°C.

🥵 Stay hydrated, limit time outdoors during peak afternoon hours, and check in on vulnerable family members, friends, and pets.