The EPA's Air Quality Index can tell you whether breathing outside air can be harmful. Here's how to read the scale to plan accordingly in Michigan.

With wildfire smoke in the forecast, track the drop in air quality across dozens of PurpleAir sensors with our live, updating maps! New data arrives every 30 minutes. Current air quality at dozens of individual PurpleAir sensors, with latest estimated smoke extent.

An air quality alert was in effect for the Chicago area and northwest Indiana Tuesday as poor air quality from unhealthy, elevated ozone and lingering wildfire smoke continues. According to the National Weather Service,