Environment Canada issues extreme heat warnings across much of Canada

Many Canadians are in for a sweltering day on Tuesday, with Environment Canada issuing extreme heat warnings for multiple provinces.

Heat warnings now cover most of Ontario along with parts of Quebec, Manitoba and the Northwest Territories, meaning millions of Canadians are going to be impacted as the temperatures soar.

Environment Canada categorizes hot weather as an extreme heat event when daily temperatures reach heat warning thresholds on two or more days in a row with no relief overnight, sometimes with high humidity.

In southwestern Ontario, including in Toronto, maximum temperatures could swing between 30 and 37 C, Environment Canada said, with humidex values ranging from 38 to 40.

Tuesday “will mark the peak of this heat event,” the alert said.

“Maximum temperatures near 37 degrees Celsius are expected this afternoon for some areas over southwestern Ontario, around the Greater Golden Horseshoe and eastern Ontario,” Environment Canada said in its alert.

Parts of Quebec could see daytime temperatures close to 30 C, while northern Manitoba could see temperatures reaching 29 C.

“A heat event continues Monday through to Wednesday for parts of northern Manitoba,” the alert said.

The agency is asking Canadians to watch for early signs of heat exhaustion in themselves and others around them.

“Signs may include headache, nausea, dizziness, thirst, dark urine and intense fatigue. Stop your activity and drink water,” it said.