The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulates (PM2.5) across the state of Michigan. Pollutants are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range Friday into Saturday morning. The Air Quality Advisory issued yesterday for the western Upper Peninsula has been expanded to cover all of Michigan. A cold front moving down from Ontario will bring wildfire smoke plumes from fires in the provinces of Manitoba and Saskatchewan into the state. The smoke plumes and associated increased PM2.5 will sink from north to south through the state from Friday morning to Saturday morning. Increased vertical mixing associated with the boundary will likely bring smoke to the surface. As a result, we anticipate PM2.5 levels rising into the Unhealthy for Sensitive Groups (USG) range across the state. There is a possibility that hourly levels could reach the Unhealthy (Red AQI) range for a short period of time. While not all locations will reach USG for PM2.5, there is enough of a threat to warrant an Advisory. It is recommended that, when possible, you avoid strenuous outdoor activities, especially those with heart disease and respiratory diseases such as asthma. Monitor for symptoms such as wheezing, coughing, chest tightness, dizziness, or burning in nose, throat, and eyes. Reduce or eliminate activities that contribute to air pollution, such as outdoor burning, and use of residential wood burning devices. Keep windows closed overnight to prevent smoke from getting indoors and, if possible, run central air conditioning with MERV-13 or higher rated filters. For up-to-date air quality data for Michigan visit the MiAir site: https://air-egle.hub.arcgis.com/ For further information, please see EPA's Air Now site for up-to- date air quality data at https://www.airnow.gov For further health information, please see MDHHS' Wildfire Smoke and Your Health site at https://www.michigan.gov/mdhhs/safety-injury- prev/environmental-health/your-health-and-wildfire-smoke. Air Quality Advisory Michigan Department of Environment, Great Lakes, and Energy May 30, 2025