Madison County, Illinois
AQI 48 · Good48
Median AQI
73
90th Percentile
260
Max AQI
304
Days with Data
Ranked #22 of 23 counties in Illinois (by median AQI, lower is better)
Monthly Median AQI — 2025
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48
Median AQI
73
90th Percentile
260
Max AQI
304
Days with Data
Ranked #22 of 23 counties in Illinois (by median AQI, lower is better)
Click a bar to view that month's details