Worst air pollution Chicago, today and tomorrow

On 18 July 2026, overall air quality in Chicago is fair. AQI is the main air quality indicator at 37.7/100. Pollution peaks around 8:00 AM (O3: 37.7/100).

On 19 July 2026, air quality conditions in Chicago will be similar to today, with AQI forecast at fair at 37.3/100. Pollution peaks around 10:00 AM (O3: 37.3/100).

Air quality in Chicago shifts across the year. In short, the cleanest stretches usually come in spring and fall, between the summer ozone season and the calmer winter pollution episodes, whereas the hottest, most humid summer days bring the year's worst ozone readings. Lake-effect winds can help clear the air on many days near the Great Lakes shoreline.

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.