Wildfire smoke has been easy to spot in Minnesota this week, coating the Twin Cities in a brownish haze that obscured the downtown skylines. But experts in lung health are more concerned about the particles you can’t see.

No rain is expected anywhere in Michigan through this weekend. While we won’t have rain we may have what looks like an occasionally cloudy sky. It won’t be clouds. It will be wildfire smoke streaming in from Canada. Here’s the smoke forecast clearly showing we will lose the strong heating of the sun at times when our sky is smoky.