Toronto is under its fifth heat warning this year, outpacing the number of heat events that happened last year, according to a meteorologist with Environment Canada. 

There were only four heat events in Toronto in 2024, said meteorologist Weiqing Zhang. This includes three that were “marginal heat events,” meaning they were not very hot or humid, she said.

“Certainly its hotter than last year,” Zhang said. 

The city has been under a heat warning for 16 days this year, including Tuesday, she said. 

The current heat warning, issued Monday morning and covering much of the Greater Toronto Area, is expected to end Tuesday night, according to Environment Canada. 

The federal weather agency first issued a heat warning on Sunday, but said the hottest conditions are expected on Monday and Tuesday. 

The region is expected to see daytime high temperatures between 30 to 33 C on Monday, Environment Canada said. With humidity, temperatures could feel like between 38 to 43 C. 

Nighttime lows are expected between 19 to 21 C, which Environment Canada said will provide little relief from the heat. 

“Confidence has increased that cooler temperatures will arrive on Wednesday, bringing an end to the heat event,” the weather agency said in a statement on Monday morning. 

The heat warning is in effect for the following areas: Toronto, Mississauga, Brampton, Vaughan, Richmond Hill, Markham, Durham Region, Newmarket, Georgina, Halton Hills, Milton and Oshawa. 

People are advised to drink water often, watch for signs of heat exhaustion and to check on those at-risk for heat illnesses, said the weather agency. 

It also suggests wearing light-colored clothing and limiting exposure to the heat.

Signs of heat stroke can include red and hot skin, dizziness and nausea. 

Over 500 spaces across Toronto are available for residents looking for relief during a heat warning, including the following air-conditioned facilities: 

North York Civic Centre Scarborough Civic Centre Etobicoke Civic Centre  York Civic Centre East York Community Centre Metro Hall lobby

The buildings will be open until 9:30 p.m. every day that a warning is in effect, with the exception of the Metro Hall lobby which is open 24 hours a day.