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.

Canadian wildfire smoke is causing poor air quality today. Those with respiratory issues should limit outdoor time. Inland highs near 90 degrees, cooler along the coast.

Hundreds of wildfires still burning in Canada are expected to undermine air quality across the Upper Midwest and Northeast into Tuesday.