Drifting wildfire smoke blankets southern Ontario, prompts air quality warnings

Smoke from wildfires in northwestern Ontario is drifting south and choking the skies over Toronto and other regions.

Environment Canada says the poor air quality may last until Thursday in some areas and warns that common symptoms of smoke inhalation include throat irritation, headache and cough.

The weather agency’s air quality warnings are active from Thunder Bay to Kingston and down to London as several First Nations communities in northwestern Ontario are under mandatory evacuation orders due to forest fires.

Environment Canada is asking people to limit their time outdoors and warning of the health risks of inhaling smoke.

The poor air quality comes as large swaths of Ontario are dealing with the second day of a heat wave that pushed humidex values as high as 45 degrees in some areas Tuesday.

When extreme heat occurs alongside poor air quality, Environment Canada advises people to prioritize keeping cool.

This report by The Canadian Press was first published July 15, 2026.