FORECAST SUMMARY: Sunday, June 22, 2025 - Monday, June 23, 2025
Ozone: 8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI), with USG (Orange, AQI) possible along the west Michigan lakeshore.
PM-2.5: 24-hour daily average Fine Particulate concentrations will range between upper Good and Moderate.
Air Quality Advisory for Sunday, June 22, and Monday, June 23, 2025
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has declared an Air Quality Advisory for June 22 and June 23, 2025, for elevated levels of ozone in western counties of Michigan. Pollutants within those areas are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range.
The Air Quality Advisory for Sunday is in effect for the following Michigan counties:
Allegan, Antrim, Benzie, Berrien, Cass, Charlevoix, Emmet, Grand Traverse, Kent, Leelanau, Manistee, Mason, Muskegon, Oceana, Ottawa, and Van Buren
The Air Quality Advisory for Monday is in effect for the following Michigan counties:
Allegan, Berrien, Cass, Kent, Mason, Muskegon, Oceana, Ottawa, and Van Buren
FORECAST DISCUSSION:
Hot temperatures and humidity continue to be the main forecast points as we move into the new week. Temperatures in the 90s, along with high humidity, remain in place, making it “feel” like 100+ degrees in parts of the state. Those with outside plans should exercise caution. Plentiful sunshine coupled with southwest winds and a warm surface and upper-level flow creates an environment favorable for ozone development. However, one component against ozone development is the high humidity in place. Increased levels of humidity can work against ozone development, even when ample sunshine is expected. There is enough threat of increased ozone along the western shoreline of Lake Michigan to warrant a continuation of an Air Quality Advisory for Sunday. The threat lingers through Monday for locations south of Ludington. However, ozone concentrations across the rest of the state should be no higher than Moderate.
By Monday, a cold front will be dropping in from the north, bringing clouds and chances for storms across the northern parts of the state. This setup will improve ozone levels further north, but ozone-conducive conditions will continue south. While increases across much of the state should not be higher than Moderate, the threat for USG ozone lingers across the central and southern western lakeshore areas; therefore, the air quality advisory for ozone has been extended through Monday for Ludington, south to the state border.
As expected, PM2.5 concentrations have slowly increased the past few days, and this trend is expected to continue. Daily averages are not expected to exceed the low to middle Moderate range.
EXTENDED FORECAST:
Extended models show the heat and humidity lingering into next week, and chances for precipitation come into play as well. This forecast will be updated Monday to determine if air quality advisories are needed later in the forecast period.
Next Forecast update: Monday, June 23, 2025