Marin County, California
AQI 21 · Good21
Median AQI
29
90th Percentile
32
Max AQI
20
Days with Data
Ranked #4 of 46 counties in California (by median AQI, lower is better)
Monthly Median AQI — 2025
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21
Median AQI
29
90th Percentile
32
Max AQI
20
Days with Data
Ranked #4 of 46 counties in California (by median AQI, lower is better)
Click a bar to view that month's details