The Michigan Air Quality Division said that 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."

Smoke from Canadian wildfires is leading to very unhealthy air quality for much of Michigan, including all of Southeast Michigan. As of noon Thursday, Detroit has the fifth-worst air quality in the world.

Smoke from wildfires in Canada has spread more than 5,000 miles, reaching parts of Russia as well as other parts of Europe during the past week.