RANKABLE EPA COUNTY AQI
St. Clair Air Quality - Illinois
EPA county-level evidence, NDS comparative intelligence, and 23 connected ZIP profiles.
Median AQI
44.0
Maximum AQI
161.0
Good-air-quality days
64.43%
Average PM2.5
9.151 ug/m3
NDS Air Quality Score
25.18
U.S. County Rank
892 of 1,049
Percentile
14.79
Grade
F
County status
St. Clair is part of the governed NDS rankable EPA county universe.
Connected ZIP codes
Methodology
EPA AQI evidence used here is county-derived. ZIP profiles connect to this evidence through the governed NDS geography relationship.