SmogRank / World / United States / Illinois / February 2025
Most polluted cities in Illinois, United States, February 2025
29 cities in Illinois, United States ranked by their average PM2.5 over the 28 days. Worst: Dolton at 9.5 µg/m³, #1,237 of 2,574 cities in the world. Cleanest: Jerseyville at 4.9. A city needs measurements on 70% of the days to be ranked.
Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.
- 1Dolton 0%
- 2Franklin Park 0%
- 2Lincolnwood 0%
- 4Calumet City 0%
- 5Naperville 0%
- 6Decatur 0%
- 7Cary 0%
- 7Chicago 0%
- 7Joliet 0%
- 10Granite City 0%
- 10Peoria 0%
- 12Brookfield 0%
- 12Elgin 0%
- 12Oak Lawn 0%
- 15Upper Alton 0%
- 15Des Plaines 0%
- 17Braidwood 0%
- 17Champaign 0%
- 19Warrenville 0%
- 20East Saint Louis 0%
- 20Bloomington 0%
- 22Wood River 0%
- 23Northbrook 0%
- 24Moline 0%
- 24Rockford 0%
- 26Springfield 0%
- 27Winthrop Harbor 0%
- 28Savoy 0%
- 29Jerseyville 0%
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
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SmogRank, most polluted cities in Illinois, United States, PM2.5, February 2025, smogrank.com/us/region/illinois/history/2025-02 (accessed 6 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.