SmogRank / Countries / United States / Illinois

Most polluted cities in Illinois, United States

26 measured cities, last 24 hours; 9 above the WHO 24-hour guideline. Worst: Wheaton at 26.7 µg/m³, #38 in the world.

26 moderate

  1. 1Wheatonlow-cost sensors 26.71.8×
  2. 2Granite City 19.01.3×
  3. 3Peoria 17.41.2×
  4. 4Evanstonlow-cost sensors 16.71.1×
  5. 5Franklin Park 16.61.1×
  6. 6Upper Alton 15.81.1×
  7. 7Calumet City 15.51.0×
  8. 8East Saint Louis 15.41.0×
  9. 9Decatur 15.21.0×
  10. 10Evergreen Parklow-cost sensors 15.01.0×
  11. 11Bloomington 14.00.9×
  12. 12Northbrook 13.80.9×
  13. 13Brookfield 13.70.9×
  14. 14Bridgeview 13.20.9×
  15. 15Oak Lawn 13.20.9×
  16. 16Chicago 12.80.9×
  17. 17Naperville 12.50.8×
  18. 18Elmwood Park 12.20.8×
  19. 19Rockford 12.20.8×
  20. 20Dolton 12.00.8×
  21. 21Elgin 11.60.8×
  22. 22Zion 11.20.7×
  23. 23Aurora 10.50.7×
  24. 24Des Plaines 10.10.7×
  25. 25Moline 9.50.6×
  26. 26Cary 9.20.6×
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Estimated: cities without a monitor

Illinois cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
North Peoria≈ 6 µg/m³Good
Waukegan≈ 5 µg/m³Good
Cicero≈ 7 µg/m³Good
Arlington Heights≈ 9 µg/m³Good
Schaumburg≈ 8 µg/m³Good
Bolingbrook≈ 9 µg/m³Good
Palatine≈ 9 µg/m³Good
Orland Park≈ 9 µg/m³Good
Tinley Park≈ 8 µg/m³Good
Berwyn≈ 7 µg/m³Good
Mount Prospect≈ 9 µg/m³Good
Normal≈ 6 µg/m³Good
Oak Park≈ 7 µg/m³Good
Hoffman Estates≈ 8 µg/m³Good
Downers Grove≈ 9 µg/m³Moderate
Glenview≈ 7 µg/m³Good
Elmhurst≈ 9 µg/m³Moderate
Lombard≈ 9 µg/m³Moderate
DeKalb≈ 7 µg/m³Good
Plainfield≈ 8 µg/m³Good
Urbana≈ 6 µg/m³Good
Belleville≈ 6 µg/m³Good
Bartlett≈ 8 µg/m³Good
Buffalo Grove≈ 9 µg/m³Good
Quincy≈ 7 µg/m³Good
Streamwood≈ 8 µg/m³Good
Crystal Lake≈ 6 µg/m³Good
Carol Stream≈ 8 µg/m³Good
Romeoville≈ 9 µg/m³Good
Rock Island≈ 8 µg/m³Good
Carpentersville≈ 8 µg/m³Good
Hanover Park≈ 8 µg/m³Good
Wheeling≈ 9 µg/m³Good
Addison≈ 9 µg/m³Moderate
Glendale Heights≈ 8 µg/m³Good
Oswego≈ 8 µg/m³Good
Woodridge≈ 9 µg/m³Good
Elk Grove Village≈ 9 µg/m³Good
Pekin≈ 5 µg/m³Good
St. Charles≈ 8 µg/m³Good

Updated 2026-10-01 22:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.