Environment Canada issues heat warning for Toronto

Environment Canada has issued a heat warning for Toronto, as the temperature with the humidex is expected to hover near 40 C on Friday.

The national weather agency issued the alert Thursday afternoon.

"A hot and humid airmass is expected to affect portions of southwestern Ontario and the Golden Horseshoe," Environment Canada said in a statement. "Humidex values near 40 are forecast for Friday afternoon."

A cold front that is expected to sweep across the region later Friday night will bring some relief. Environment Canada says the mercury is expected to drop to a low of 15 C Friday night, bringing the temperatures to near-seasonal values for the weekend.