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.

Millions of people across the Upper Midwest and the Northeast are under air quality alerts Monday, as smoke from wildfires in Canada drift over the region

The National Weather Service reported an updated air quality alert at 10:15 a.m. on Monday in effect until 11:15 p.m. for Northern Worcester and Southern Worcester as well as Franklin, Middlesex, Essex,