RANKABLE EPA COUNTY AQI
Mason Air Quality - Washington
EPA county-level evidence, NDS comparative intelligence, and 9 connected ZIP profiles.
Median AQI
21.0
Maximum AQI
67.0
Good-air-quality days
92.59%
Average PM2.5
N/A
NDS Air Quality Score
85.56
U.S. County Rank
79 of 1,049
Percentile
92.56
Grade
A
County status
Mason 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.