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.

Canadian wildfires burning across northern Manitoba and Saskatchewan are sending smoke through central Canada, the Great Lakes region and the northeastern United States, reducing air quality and visibility in major cities. Forecasters said they were “optimistic” that the lingering wildfire smoke would ease later in the day on Tuesday.

Degraded and/or unsafe air quality levels will continue across parts of Canada Monday as wildfire smoke lingers. However, the air quality will begin to improve as the week progresses, from west to eas