Although the majority of wildfires are occurring in western Canada, smoke from these fires has been drifting eastward, impacting air quality in areas around the Great Lakes and the U.S. Northeast, shows AirNow, the Environmental Protection Agency's interactive air quality map.

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."