RANKABLE EPA COUNTY AQI
Fergus Air Quality - Montana
EPA county-level evidence, NDS comparative intelligence, and 14 connected ZIP profiles.
Median AQI
44.0
Maximum AQI
87.0
Good-air-quality days
92.22%
Average PM2.5
3.949 ug/m3
NDS Air Quality Score
54.83
U.S. County Rank
492 of 1,049
Percentile
52.96
Grade
C
County status
Fergus is part of the governed NDS rankable EPA county universe.
Methodology
EPA AQI evidence used here is county-derived. ZIP profiles connect to this evidence through the governed NDS geography relationship.