Toronto recorded among the worst air quality of all major cities worldwide on Wednesday as thick smoke from wildfires in Ontario blanketed its skyline and drifted into the US, prompting health warnings.

As of Tuesday night, just under 200 total active wildfires have been reported, according to the province.

A massive plume of smoke from wildfires burning across Canada has swept into the United States, degrading air quality across the Midwest, Northeast and Mid-Atlantic.

Environment Canada has issued health warnings after sky over city turns yellow