RANKABLE EPA COUNTY AQI
San Mateo Air Quality - California
EPA county-level evidence, NDS comparative intelligence, and 37 connected ZIP profiles.
Median AQI
27.0
Maximum AQI
73.0
Good-air-quality days
88.09%
Average PM2.5
5.290 ug/m3
NDS Air Quality Score
83.23
U.S. County Rank
97 of 1,049
Percentile
90.84
Grade
A
County status
San Mateo 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.