FORECAST SUMMARY: Friday, June 12, 2026 - Monday, June 15, 2026
Ozone: 8-hour average Ozone concentrations in the Good (AQI Green) to Moderate (AQI Yellow) range during the end of the week will improve to all Good Sunday and Monday.
PM-2.5: 24-hour daily average Fine Particulate concentrations will average mostly Good through the period; Saturday has the best chance for low-Moderate concentrations.
FORECAST DISCUSSION:
High pressure is building in behind Thursday’s cold front, which brought storms, some strong in nature, across Michigan. Westerly winds on Friday will deliver cooler, drier air, keeping temperatures mainly in the 70s and making for a pleasant end to the workweek. The next system arrives late Friday in the northwest and progresses southeast through early Sunday. A reinforcing surge of cooler air follows this boundary, bringing Sunday highs down into the 60s to lower 70s.
Ozone levels have generally ranged between Good and Moderate this week. One monitor in the far southwest briefly reached low-end USG prior to Thursday’s storms. The cooler westerly flow behind the front should limit ozone formation, keeping concentrations in the Good category on Friday. Warmer, southwesterly winds on Saturday could support some Moderate ozone, and there is a small potential for a brief period of low-end USG along portions of the central and southwest lakeshore. At this time, the risk is not high enough to justify issuing an Air Quality Alert. Cooler surface and upper-level temperatures behind the weekend boundary will support Good ozone levels Sunday and Monday.
Fine particulate concentrations have remained low this week, with most sites reporting Good AQI and only a few locations reaching low‑Moderate levels. Westerly flow and a low regional background should keep readings mostly Good on Friday. A period of southerly winds on Saturday may allow levels to rise into the low‑Moderate range across southern Michigan. However, the weekend boundary moving through the state will help disperse particulates, and Good AQI is expected again Sunday and Monday.
EXTENDED FORECAST:
Good air quality continues into the extended period.
Next Forecast update: Monday, June 15, 2026