Environment Canada has issued a heat warning for Windsor, Leamington, and Essex County that's expected to last 48 hours.
"A hot and humid air mass is expected to arrive Wednesday through Thursday, bringing daytime high temperatures near 31 C with humidex values near 40 C," the weather agency said in an advisory.
Thursday's daytime high could peak at 34 C with humidex values near 43 C.
"Hot and humid air can also bring deteriorating air quality and can result in the air quality health index approaching the high-risk category," Environment Canada said.
Windsor-Essex won't get much relief overnight, either. The overnight low is not likely to fall below 22 C Wednesday night.
The region can expect another hot day on Friday, but a cooler air mass is forecast for Saturday.