FORECAST SUMMARY: Wednesday, July 22, 2026 - Thursday, July 23, 2026
PM-2.5: Concentrations will range from Good (Green AQI) to Moderate (Yellow AQI) with the highest levels in the upper peninsula Thursday.
Ozone: 8-hour average Ozone concentrations in the Good (Green AQI) to Moderate (Yellow AQI) range will continue.
FORECAST DISCUSSION:
Air quality readings Wednesday morning were Good across the state, a welcome change from conditions over the past week or so. High pressure and a northerly wind flow will bring cool, dry weather through the day. As the high shifts east Thursday into Friday, winds will turn westerly and then southwesterly. This change in wind direction will support a steady warming trend toward the end of the week.
Fires are ongoing across parts of Ontario, but recent rainfall in those areas has kept smoke production low. As a result, even with northerly winds, we have not seen increases in PM2.5 from wildfire smoke. However, several fires are also burning across the central and northwestern provinces of Canada. Smoke from these fires has already moved into North Dakota, and westerly winds on Thursday are expected to push these plumes eastward into the upper peninsula. At this time, we do not anticipate daily averages of PM2.5 to exceed Moderate, but a few hours of Unhealthy for Sensitive Groups (USG) is possible in the western upper peninsula.
Sunshine and rising surface temperatures will create a more ozone conducive environment toward the end of the week; however, upper‑level temperatures remain cool, which usually helps limit ozone formation. Forecasting ozone can be challenging when wildfire smoke is present, but at this time we expect only gradual increases over the next few days. Concentrations higher than Moderate are not anticipated.
EXTENDED FORECAST:
Warmer and drier conditions late in the week may allow the fires across Ontario to become more active. We are monitoring this closely to determine whether any resulting increase in pollution may warrant future Air Quality Alerts.
Next Forecast update: Thursday, July 23, 2026