Heat warning as humidex could reach 43 in parts of southern Ontario

A heat warning remains in place for parts of southern Ontario.

Southwestern portions of the region including Windsor, Sarnia, and Chatham-Kent are under the yellow weather alert from Environment Canada.

Forecasters said a “heat event” continues on Thursday.

Daytime highs of 31 C to 33 C are expected with overnight lows near 21 C.

Humidex values between 39 and 43 are also in the forecast.

Locations near Lake Erie and Lake Huron might be slightly cooler, forecasters said.

“Although temperatures on Friday and Saturday will climb into the upper twenties to near 30 degrees Celsius, humidity levels are expected to be lower,” Environment Canada said.

“Take action to protect yourself and others – extreme heat can affect everyone’s health.”

Meanwhile, there is also a risk of thunderstorms in southern Ontario on Thursday and Friday.

Areas shaded in yellow are under a heat warning. (Environment Canada)