Chicago’s air quality is some of the worst in the U.S., according to a recent study from the American Lung Association (ALA).
The ALA’s 2025 State of the Air report ranks the Chicago region among the worst in the nation for both particle pollution and ozone levels.
Chicago ranked 15th highest out of 228 U.S. metro regions for high ozone days, and 53rd highest for 24-hour particle pollution days out of 225 metro areas.
Additionally, Chicago ranked 13th worst for annual particle pollution days out of 208 metropolitan areas.
What is driving air pollution in Chicago?
The good news is that man-made pollution in Chicago is on the decline, according to the ALA.
The main factor driving increased pollution in Chicago and other U.S. metro areas is particulate matter from wildfire smoke.
During the summer of 2023, Canadian wildfires caused heavy smoke to blanket Chicago for extended periods, leading to a dramatic drop in the Windy City’s air quality.
Wildfires are increasing in intensity and scale due to extended droughts and rising global temperatures, according to ALA research.
Who is most at risk?
Poor air quality in Chicago affects us all, but certain demographics are more at risk for adverse health complications due to particle pollution.
According to the ALA, pregnant women, children, and the elderly are at elevated risk for negative health complications related to air pollution.
Additionally, immunocompromised individuals, namely those with lung conditions and cardiovascular disease, are at increased risk.
How can Chicagoans stay safe?
Protecting oneself from air pollution means staying informed. Chicagoans can stay up to date on daily air quality levels by following the National Weather Service’s Air Quality Index.
The online index tracks air quality levels nationwide, ranking levels from Good to Hazardous, and issuing recommendations based on each level.
During periods of elevated air pollution, the National Weather Service recommends the following safety precautions:
- Limit time outdoors
- Stay inside with windows and doors secured shut
- Avoid strenuous physical activity
- Run your air conditioning unit and consider installing a high-efficiency filter
- Avoid burning anything
- Talk to your doctor if you believe you’re at elevated risk or have been exposed to pollutants for an extended period