Extreme heat grips Canada as Environment Canada issues multiple weather alerts

Large parts of Canada are under Environment Canada weather warnings as extreme heat, poor air quality and the threat of severe thunderstorms affect several provinces.

Heat warnings are in place across most of Ontario, as well as parts of Manitoba, Saskatchewan and the Northwest Territories.

Temperatures are expected to reach the mid to high 30s Celsius, with humidex values making it feel like the mid-40s.

In Quebec and New Brunswick, Environment Canada has warned of potentially dangerous thunderstorms.

An orange tornado watch has been issued for areas between Montreal and Quebec City, including Drummondville, Trois-Rivieres and Shawinigan.

“Significant damage or destruction to infrastructure, homes and the natural environment is possible,” the tornado watch states.

Environment Canada meteorologist Geoff Coulson said a large high pressure system centred over the United States is driving the unusually hot conditions.

“It's a wide-ranging system that's bringing much above seasonal temperatures,” Coulson said.

Ottawa was forecast to reach 35C, while Toronto was expected to hit 37C, putting both cities in contention to break daily temperature records.

Much of northern Ontario remains under an orange heat warning, while yellow heat warnings cover most southern regions.