Barrie braces for ‘peak’ of Ontario heat wave today as humidex nears 45

People cooling off at the beach in Barrie, Ont., during the heat wave on July 13, 2026. (CTV News/Steve Mansbridge)

Barrie is bracing for another scorching hot day in the city.

Environment Canada says Tuesday will mark the peak of the ongoing heat event across Ontario, with some areas expected to reach 37 C and humidex values making it feel as hot as 45.

The hottest conditions will be felt across southwestern Ontario, the Greater Golden Horseshoe and eastern Ontario, where extreme heat and humidity will mix to create dangerous conditions.

• Multi-day heat wave to grip Central Ontario. Here’s how to beat the 45 humidex

Overnight temperatures in the Barrie area will sit around 20 and 25 C.

This heat warning is expected to end tonight, but weather experts say it could continue into Wednesday or Thursday for much of southern Ontario.

Health officials remind residents to stay hydrated, avoid strenuous outdoor activities during the hottest part of the day and stay in air-conditioned places.

Heat exhaustion symptoms

Symptoms of heat exhaustion include headache, nausea, dizziness, thirst, dark urine and extreme tiredness. Anyone showing signs of heat stroke, such as confusion, hot red skin or loss of consciousness, should call 911 immediately.

Environment Canada also reminds residents to never leave children or pets unattended in parked vehicles.