Heat warning issued for Toronto and southern Ontario as temperatures soar 

24 July,2025

RED FM News Desk

The Greater Toronto Area and several parts of southern Ontario are under a heat warning as scorching temperatures pushed the mercury up to 35°C today. 

Environment Canada has issued the alert for regions along Lake Ontario — from St. Catherines to Toronto — where humidex values could make it feel as hot as 44°C. 

While daytime conditions will be sweltering, overnight temperatures are expected to dip to between 20°C and 23°C, offering some relief from the extreme heat. 

The heat is forecast to ease slightly by Friday, with daytime highs around 30°C and humidex values near 40°C. 

This isn’t the first heat warning for Ontario this summer — last month’s heat wave shattered temperature records across the province, with extreme heat reaching the mid-30s in several regions. 

During periods of extreme heat, health officials urge residents to stay hydrated, watch for symptoms of heat exhaustion, and check on vulnerable individuals, including seniors and those with pre-existing health conditions.