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.

The Dragon Bravo Fire has destroyed dozens of structures and a water treatment facility, and the White Sage Fire, located in Kaibab National Forest, has forced hundreds to evacuate.

“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.

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.

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.

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.

The Chicago area recorded ozone levels of 156 late Monday afternoon. Levels above 100 are considered unhealthy. Residents with respiratory issues, children and the elderly are advised to stay indoors and limit exposure to air outside until Tuesday evening.

Federal firefighters initially tried to manage the Dragon Bravo Fire with a confine-and-contain strategy. Arizona state officials say this was a grave mistake.