Washington County, Oregon
AQI 36 · Good36
Median AQI
54
90th Percentile
88
Max AQI
182
Days with Data
Ranked #17 of 21 counties in Oregon (by median AQI, lower is better)
Monthly Median AQI — 2025
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36
Median AQI
54
90th Percentile
88
Max AQI
182
Days with Data
Ranked #17 of 21 counties in Oregon (by median AQI, lower is better)
Click a bar to view that month's details