FORECAST SUMMARY: Sunday, August 10, 2025 - Monday, August 11, 2025
Ozone: 8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).
PM-2.5: 24-hour daily average Fine Particulate concentrations will average mostly Moderate with Unhealthy for Sensitive Groups (USG, Orange AQI) range possible in the Upper Peninsula on Monday.
Air Quality Advisory for the Upper Peninsula on Monday, August 11th until noon on Tuesday, August 12th
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulate (PM2.5) across the Upper Peninsula of Michigan. Pollutants within those areas are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range.
The Air Quality Advisory includes the following counties:
Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Menominee, Ontonagon, Schoolcraft
FORECAST DISCUSSION:
This forecast update is warranted due to wildfire smoke entering the Upper Peninsula of Michigan starting Monday morning. This is happening as a low-pressure area to our north across Ontario moves northeast, bringing a cold front towards the Great Lakes region. Hourly levels of PM2.5 on Sunday morning were in the USG to Unhealthy range across the Dakotas as northerly winds behind the boundary pulled smoke plumes south.
As the front tracks east Sunday into Monday, the smoke plume moves east as well. Wildfire smoke is expected to enter the western Upper Peninsula early Monday, pushing east through the day. At this point it looks like smoke should stay north and west of the Lower Peninsula; however, current weather and smoke models will be evaluated Monday morning to determine if the air quality advisory will need to be expanded into other parts of the state. Levels of PM2.5 in the USG range are likely Monday across the Upper Peninsula with some locations reaching the Unhealthy (Red, AQI) range for a few hours. Levels across the rest of the state will range mostly Moderate.
Muggy conditions and clouds associated with storm chances will keep ozone from reaching higher than Moderate Sunday or Monday.
EXTENDED FORECAST:
Smoke could linger on Tuesday along with chances for precipitation. High pressure then moves in past mid-week.
Next Forecast update: Monday, August 11, 2025