Sonoma County, California
AQI 9 · Good9
Median AQI
18
90th Percentile
39
Max AQI
273
Days with Data
Ranked #2 of 46 counties in California (by median AQI, lower is better)
Monthly Median AQI — 2025
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9
Median AQI
18
90th Percentile
39
Max AQI
273
Days with Data
Ranked #2 of 46 counties in California (by median AQI, lower is better)
Click a bar to view that month's details