FORECAST SUMMARY: Tuesday June 30th, 2026, through Wednesday July 1st, 2026
Ozone:
Ozone concentrations are expected to be in the Moderate (Yellow AQI) to Unhealthy for Sensitive Groups (Orange AQI) range.
PM-2.5:
PM-2.5 concentrations are expected to be in the Moderate (Yellow AQI) range.
Air Quality Alert for June 30, 2026, for the following west Michigan counties:
Muskegon, Ottawa, Kent, Allegan, Van Buren, Berrien
FORECAST DISCUSSION:
The heat wave has officially commenced with Extreme Heat Warnings and Heat Advisories in place across the entire region. With the heat and sunlight brings a threat of Ozone development, especially along the lakeshore in west Michigan where there is currently an Air Quality Alert in place for today. Models and model guidance suggest Unhealthy for Sensitive Groups Ozone concentrations along the lakeshore and into Kent County later this afternoon due to the hot temperatures, ample sunlight, and southwest flow which is typically a classic Ozone set up for that area. However, accompanying the heat and sunlight are rather high dew points which have eclipsed 70s degrees with some approaching the mid-70s. As mentioned in previous forecast updates, whenever dew points reach or exceed 70 degrees, Ozone does not develop when it otherwise would when dew points are lower. It will be interesting to observe Ozone concentrations this afternoon during peak heating time along the lakeshore, especially with a lake breeze currently setting up which may bring Ozone over the lake, more ashore.
It is because of the uncertainty of the Ozone and dew points interaction that I am holding off on issuing another Air Quality Alert for west Michigan tomorrow, Wednesday. The current Alert is in place until midnight tonight so I will be watching concentrations all afternoon, in case updates are needed. Dew points are expected to remain in the low to mid 70s overnight and through tomorrow, along with clouds popping up from the moisture available in the atmosphere. However, depending on what happens with Ozone today, an Alert may be issued tomorrow morning.
Aside from Ozone, with southerly flow and high dew points in the atmosphere above Michigan, PM2.5 will be increasing into the Moderate range this week. Also, as news headlines have mentioned, Saharan Dust will be entering the Great Lakes today, Tuesday, and into Wednesday but it is expected to remain elevated in the atmosphere while providing colorful sunrises and sunsets and not impacting air quality.
EXTENDED FORECAST:
The extreme heat continues through the rest of this week with Ozone and PM2.5 remaining in the Moderate range.
Next Forecast update: Wednesday July 1st, 2026