Smoke from Canadian wildfires is leading to very unhealthy air quality for much of Michigan, including all of Southeast Michigan. An air quality alert is in effect for all of Southeast Michigan until noon on Friday.

The Michigan Air Quality Division said as smoke from Canadian wildfires continues to threaten the upper Midwest, "monitors in the western (Upper Peninsula) showed a large increase surface concentrations, during Tuesday, as smoke mixed down, which sent PM-2.5 concentrations soaring into the Unhealthy and higher range."

As Canadian wildfires burn, northern Michigan areas and the Upper Peninsula have been upgraded to an air quality alert. Here's what to know.