Multiple U.S. states and Canadian provinces are experiencing poor air quality from wildfire smoke. Here's where.

Wildfire smoke degrades air quality in swaths of Ontario, with Toronto ranking among the worst in the world on Monday.

“Several other wildfires are still active in Colorado, including the Sowbelly Fire in the Dominguez-Escalante National Conservation Area, the South Rim Fire in Black Canyon of the Gunnison National Park and wildfires in Mesa County,” the outlet reported.

Five wildfires are burning on thousands of acres in western Colorado, including one that crossed into the state from Utah, fire officials said Sunday.

At least four firefighters have been injured over the last week while battling three wildfires in Northern California forests that are burning amid extreme heat in steep, bone-dry terrain, fire officials said Monday.

Gov. Jared Polis issued a disaster declaration Sunday for five wildfires burning in several of the state's counties — here's what you need to know.

Heavy winds that swept through Black Canyon of the Gunnison National Park on Sunday night started “rapid fire spread” after a relatively slow day of growth, according to fire officials.

Wildfire smoke has made its return to Central Oregon skies. As wildfires continue to burn around the region, many residents are waking up to hazy skies, air quality alerts and the lingering smell of smoke.

Wildfires have scorched hotspots in several Mediterranean countries this month, with blazes forcing thousands of people into lockdown in Catalonia in Spain, and encroaching on France's second-biggest city of Marseille.