SmogRank / World / United States / Illinois / March 2024
Most polluted cities in Illinois, United States, March 2024
21 cities in Illinois, United States ranked by their average PM2.5 over the 31 days. Worst: Granite City at 9.8 µg/m³, #438 of 1,643 cities in the world. Cleanest: Cary at 5.1. A city needs measurements on 70% of the days to be ranked.
OpenAQ's archive, where our readings come from, has almost none from the United States for March 20, 2024: cities in the United States have it from the EPA's own records of the same monitors. Why.
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.
- 1Granite City 0%
- 2East Saint Louis 0%
- 3Oak Lawn 0%
- 4Naperville 0%
- 5Decatur 0%
- 5Springfield 0%
- 5Bloomington 0%
- 8Wood River 0%
- 8Brookfield 0%
- 8Chicago 0%
- 11Peoria 0%
- 12Braidwood 0%
- 13Calumet City 0%
- 13Franklin Park 0%
- 13Savoy 0%
- 16Rockford 0%
- 17Moline 0%
- 18Northbrook 0%
- 19Des Plaines 0%
- 20Winthrop Harbor 0%
- 21Cary 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
All cities in the world, March 2024 · All cities in United States, March 2024 · Illinois now
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SmogRank, most polluted cities in Illinois, United States, PM2.5, March 2024, smogrank.com/us/region/illinois/history/2024-03 (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.