Heat warning in place across Greater Toronto Area starting Saturday

Environment Canada has issued a multi-day heat warning for some cities in southern Ontario starting on Saturday, including Toronto, Hamilton and the Halton, Peel regions. 

This heat warning is Toronto's sixth this year. Daytime temperatures of over 30 C are expected throughout southern Ontario, particularly along the Highway 401 corridor between Windsor and Ottawa, a meteorologist with Environment Canada told CBC Toronto.

The hottest days are expected to be Sunday and Monday, reaching about 33 C, Crawford Luke said. Humidity levels are expected to be slightly less severe this weekend compared with previous heat waves this summer, making it feel like upwards of 35 C, Environment Canada said in its warning.

Nighttime lows of around 20 C will provide little relief, particularly in big cities like Toronto due to the "urban heat island effect," Luke said. 

Hot temperatures are expected to continue throughout the month, though he said next week could cool off slightly. 

"It's entirely possible that we get … another heat warning or heat wave later in August or even into September," Luke said.

Advice to help beat the heat

Environment Canada is advising people to limit time outside during the hottest hours of the day, between noon and 7 p.m. and to drink water often, Luke said. 

If possible, he said outdoor workers should try to take more frequent breaks, drink more water and try to periodically get under the shade or go indoors.

"Take it easy, listen to your body and don't overdo it," Luke said. 

People are advised to watch for symptoms of heat stroke. Symptoms can include red and hot skin, dizziness, nausea, confusion and change in consciousness levels.

In a social media post, the City of Toronto reminded residents to stay hydrated and keep cool.

"If you know someone without A/C, invite them into your place if you have a cool space. Take care of each other," the city said.