What is the air quality in Chicago IL?

Chicago IL, United States of America has an annual US AQI of 56 (Reasonable) and average PM2.5 of 12.4 µg/m³, ranking #1502 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Chicago IL?

October is typically the cleanest month (AQI 50) and February the most polluted (AQI 61).

Where does Chicago IL's air quality data come from?

PM2.5: 1998–2026 (monitors 1998–2026, satellite 1998–1999; 2026 provisional (AirNow)). Measured by government monitoring stations. Full sources are on the methodology page.

Chicago IL, United States of America — Air Quality & Clean City Guide 2026

Chicago IL Air Quality Data

Global rank	City	Continent	AQI	PM2.5
1502	Chicago IL, United States of America	North America	AQI 56	PM2.5 12.4 µg/m³