Cowlitz County, Washington
AQI 21 · Good21
Median AQI
46
90th Percentile
72
Max AQI
190
Days with Data
Ranked #9 of 31 counties in Washington (by median AQI, lower is better)
Monthly Median AQI — 2025
Click a bar to view that month's details
21
Median AQI
46
90th Percentile
72
Max AQI
190
Days with Data
Ranked #9 of 31 counties in Washington (by median AQI, lower is better)
Click a bar to view that month's details