As scorching temperatures descend upon the Toronto area this weekend, a senior climatologist says to expect longer and hotter heat waves this summer.

The city and neighbouring municipalities are currently under a heat warning. Environment Canada said the “heat event,” which sees the temperature soar above 30 C, is expected to continue Sunday and may last through early next week.

Climatologist David Phillips told CP24 that the city already broke a record at 2 p.m. when the temperature rose to 31 C. According to Environment Canada, the highest temperature recorded for June 5 is 30 C set in 1940.

Phillips noted that this weekend's heat wave is a little early as it usually occurs during the dog days of summer, which will not officially begin until June 20.

"What's makes this one particularly torrid and sweltering and sizzling is the fact that we're going to see four or five days where the temperature is going to get above a 30 with fairly decent humidex values, too," Phillips said.

He added that the first heat wave is always the toughest as people struggle to get used to scorching temperatures.

Phillips said he is also concerned about hot nights.

"When we see mortality and morbidity statistics from heat, it is often the very warm nights. That's where we see most stress. And so, we see some (overnight) temperatures above 20 (in the next few days). That's a tropical night in the Toronto area," he said.

According to the forecast, Phillips said this year's summer season will be warmer than normal.

"There's going to be more of this, and they could be longer and more intense heat," Phillips said.

On Saturday, the city opened eight cooling centres where people can find relief from the heat. They include East York Civic Centre, Etobicoke Civic Centre, North York Civic Centre, Scarborough Civic Centre, Domenico Di Luca Community Centre, Don Montgomery Community Centre, Masaryk-Cowan Community Recreation Centre, and Metro Hall.

Seven locations will be running from 11 a.m. to 7 p.m., while Metro Hall will run for 24 hours.

The city said COVID-19 protocols will be in place at the centres to prevent the spread of the virus.

Residents looking to beat the heat can also visit the city's splash pads operating daily from 9 a.m. to 8:30 p.m. Toronto also opened Saturday its supervised program at 10 of its beaches.

The sun will be out again on Sunday with a high of 33 C and a humidex of 36. On Monday, it will be a mix of sun and cloud and a high of 31 C.

Relief from the dry and hot conditions may be coming starting on Tuesday. According to the forecast, it will be cloudy with a 40 per cent chance of showers that day. The high will be 29 C.