Heat warning issued as Toronto braces for temperatures near 40 C

From wildfire-fueled apocalyptic orange skies to thunderstorms, Toronto has had a wild ride of summer weather. After unseasonably cool weather in July, the mercury is quickly climbing once again, triggering this summer's latest heat warning issued by Environment Canada earlier today.

Temperatures in the high twenties to low thirties are anticipated for Wednesday, Thursday, and possibly Friday. While well within the seasonal range, the compounding effects of high humidity will be the factor that really cranks up the heat in the coming days, with humidex values expected to drive temperatures soaring into the 40+ zone.

Don't expect nightly reprieves from the sweltering heat. Environment Canada predicts that temperatures will remain above 20 degrees each night. 

The heat warning recommends seeking cool places or air-conditioned areas to avoid prolonged exposure to the heat, though these options can be hard to come by, especially for those experiencing homelessness or living in marginalized communities. 

The City operates 13 emergency cooling centres, which have been strategically placed in communities like St James Town and Jane & Finch to better serve populations less likely to have access to air conditioning. 

CBC reported on Sunday that the city would not be opening its emergency cooling centres until an official heat warning was in place. This afternoon's announcement means that the cooling centres will now be accepting drop-ins.

High temperatures won’t be limited to Toronto, with the latest round of heat warnings extending to cover practically all of Southern Ontario.

*HEAT WARNING: Extended to include a larger area of southern Ontario including Toronto and all of the GTHA pic.twitter.com/OYIRP4eCWI

— 680 NEWS Weather (@680NEWSweather) August 10, 2021

This latest blast of hot weather coincides with a continent-wide wave of wildfires that have drastically affected air quality in Toronto.

Hot and humid weather is already a significant contributor to poor air quality, as measured by the province's Air Quality Health Index. Shifting winds could once again bring wildfires back into the mix.

Environment Canada predicts a wave of cooler, less humid air will arrive by Friday or the weekend, bringing conditions back to seasonal as the city tries to make the most of a limited but much-anticipated patio season.