Worst air pollution Old Fourth Ward - Ann Arbor, today and tomorrow

On 30 August 2026, overall air quality in Old Fourth Ward is fair. AQI is the main air quality indicator at 36.9/100. Pollution peaks around 11:00 AM (O3: 36.9/100).

On 31 August 2026, air quality conditions in Old Fourth Ward will be similar to today, with AQI forecast at fair at 36.2/100. Pollution peaks around 8:00 AM (O3: 36.2/100).

Winter tends to bring the year's worst particulate spikes here, as cold, stagnant air traps heating and traffic emissions close to street level through the winter. As the weather warms, ozone typically overtakes particulate matter as the top concern here, as intense summer sunlight bakes traffic emissions into ground-level ozone across the urban core. Spring and autumn tend to offer a breather, with steadier winds helping keep pollutant levels down.

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.

During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.