Wisconsin air quality among nation's worst as Canadian wildfire smoke spreads

A calm lake with green vegetation in the foreground, tree-lined shores, and a wooden dock extending from the right side under a hazy sky.

Wisconsin air quality among nation’s worst as Canadian wildfire smoke spreads

The Upper Midwest was contending with the worst air quality in the country Thursday. And, for much of the day, Milwaukee had the worst air quality of any major U.S. city, according to a ranking from IQ Air.