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.

Millions in the United States are facing another day of hazy skies fueled by hundreds of smoky wildfires burning across North America, impacting air quality in parts of the U.S. and raising health concerns.

At least three people have been injured and hundreds of homes and businesses are at risk in California as a massive wildfire spreads across the Los Padres National Forest. Smoke blowing over Las Vegas from the California wildfire created a hazy sky and poor air quality over Sin City Monday.