Toronto heat warning enters fifth straight day as temperatures near 30 C

People take in the sights at High Park in Toronto, on Tuesday, Aug. 22, 2023. THE CANADIAN PRESS/Spencer Colby

The city of Toronto remains under a heat warning for a fifth consecutive day as hot and humid conditions continue to linger across the city.

Environment Canada says daytime highs today will reach around 30 C, while overnight temperatures are expected to remain near 20 C, providing little relief from sweltering heat that hasn’t led up since June 30.

• Your hourly and 7-day forecast on our CP24.com weather hub

The national weather agency says the long-duration heat event is expected to continue but also warn the combination of heat and humidity could lead to deteriorating air quality, with the Air Quality Health Index potentially approaching the high-risk category.

Today’s forecast calls for showers ending late this morning, followed by a mix of sun and cloud with a 40 per cent chance of additional showers. There is also a risk of a thunderstorm, but officials did not specify at what time that could occur.

“We call hot weather an extreme heat event when daily temperatures reach heat warning thresholds on 2 or more days in a row with no relief overnight, sometimes with high humidity,” officials wrote online, adding that weather conditions play a big role in how the body regulates its temperature.

“If it’s windy, sweat evaporates faster, which helps to cool you. But high humidity slows down this process, contributing to increased body temperature.”

Some common heat illnesses include:

• Heat rash
• Heat cramps (muscle cramps)
• Heat edema (swelling of hands, feet, and ankles)
• Heat syncope (fainting)
• Heat exhaustion
• Heat stroke

Residents are advised that those most at risk are older adults, infants and young children, people with chronic illnesses and people experiencing homelessness.