Snohomish County, Washington
AQI 41 · Good41
Median AQI
62
90th Percentile
87
Max AQI
243
Days with Data
Ranked #28 of 31 counties in Washington (by median AQI, lower is better)
Monthly Median AQI — 2025
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41
Median AQI
62
90th Percentile
87
Max AQI
243
Days with Data
Ranked #28 of 31 counties in Washington (by median AQI, lower is better)
Click a bar to view that month's details