Jefferson County, Washington
AQI 19 · Good19
Median AQI
36
90th Percentile
59
Max AQI
230
Days with Data
Ranked #7 of 31 counties in Washington (by median AQI, lower is better)
Monthly Median AQI — 2025
Click a bar to view that month's details
19
Median AQI
36
90th Percentile
59
Max AQI
230
Days with Data
Ranked #7 of 31 counties in Washington (by median AQI, lower is better)
Click a bar to view that month's details