An air quality alert is in effect for all of Massachusetts today due to smoke from Canadian wildfires, and it could be the worst air quality day the Boston area has seen all year. The Massachusetts Department of Environmental Protection issued an alert for "fine particulates" in the air until midnight.

Wildfires burning in Canada were causing unhealthy air quality across parts of North America on Monday. 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.

Air quality concerns continue to expand from the Upper Midwest through the Great Lakes region and into the Northeast and New England as wildfire smoke from Canada drifts southward into the U.S.