Smoke produced by hundreds of wildfires burning across Canada has drifted thousands of miles and nearly circled the entire globe, with hazy skies now seen across parts of North America, Europe and even parts of Russia.

As Canada grapples with one of its worst wildfire seasons on record, smoke from the blazes have prompted air quality alerts across the U.S.

Canada is battling more than 700 active wildfires across the country, roughly two-thirds of which are burning out of control, according to the Canadian Interagency Forest Fire Center (CIFFC). Smoke billowing from the blazes has blanketed central Canada and the northern U.S., prompting widespread air quality alerts.