Good morning! A heat warning remains in effect for Toronto, but compared to what's coming the next few days it will feel relatively comfortable out in the sun today.

As of 6:30 a.m. it was 18 C in the city. Mainly sunny skies are on tap for your Tuesday with a high of 31 C, feeling more like 34 C with the humidity.

The clouds will start to roll in this evening with a 30 per cent chance of showers, risk of thunderstorms and an overnight low of 23 C.

It will probably feel like over 40 tomorrow

Heat warnings are in effect from both Environment Canada and Toronto's acting medical officer for your Tuesday as a hot and humid air mass makes its way into the city from the United States this afternoon. 

The humidity is expected to get worse as the day goes on into this evening. If you're wondering how bad it will get look no further than tomorrow when the humidity is expected to make temperatures feel in the high 30s or early 40s.

Humid conditions are supposed to stick around through Friday leading to what Environment Canada says could be the "longest and most significant heat wave of the summer so far."

People in Toronto are advised to reschedule outdoor activities or plan them for later in the evening during a heat warning.

The hot weather could break on Friday when a weak cold front is expected alongside a thunderstorm. If that cold front arrives there might be some relief from the steamy weather for your weekend.

The city says that air-conditioned shopping malls, 170 libraries and community centres are open to the public to provide relief from the heat. Seven cooling centres are also open across Toronto at the following locations:

  • Metro Hall - 55 John St. (7:30 a.m. to 9:30 p.m.).
  • East York Civic Centre - 850 Coxwell Ave. (7:30 a.m. to 9:30 p.m.).
  • North York Civic Centre - 5100 Yonge St. (7:30 a.m. to 9:30 p.m.).
  • Driftwood Community Centre - 4401 Jane St. (11 a.m. to 7 p.m.).
  • Etobicoke Civic Centre - 399 The West Mall (7:30 a.m. to 9:30 p.m.).
  • McGregor Community Centre - 2231 Lawrence Ave. E. (11 a.m. to 7 p.m.).
  • Centennial Community Centre - 1967 Ellesmere Rd. (11 a.m. to 7 p.m.).

Environment Canada issues a heat warning in two situations:

  • When daytime temperatures are expected to hit 31 C or higher on two consecutive days, and nighttime temperatures are predicted to stay at 20 C or higher.
  • When the humidex is expected to hit 40 C or higher for two consecutive days.