Counties with the Cleanest Air in Washington
The top 25 of 31 Washington counties on GIS Map, ranked by lowest median Air Quality Index, counting only counties that host an EPA air monitor.
| # | County | Median AQI |
|---|---|---|
| 1 | Pacific County | 16 |
| 2 | Garfield County | 17 |
| 3 | Klickitat County | 17 |
| 4 | Adams County | 18 |
| 5 | Kitsap County | 19 |
| 6 | Franklin County | 20 |
| 7 | Grays Harbor County | 20 |
| 8 | Whitman County | 20 |
| 9 | Jefferson County | 21 |
| 10 | Mason County | 21 |
| 11 | Cowlitz County | 22 |
| 12 | Lewis County | 22 |
| 13 | Kittitas County | 23 |
| 14 | Walla Walla County | 24 |
| 15 | Grant County | 26 |
| 16 | Skagit County | 26 |
| 17 | Thurston County | 26 |
| 18 | Chelan County | 28 |
| 19 | Clark County | 31 |
| 20 | Whatcom County | 33 |
| 21 | Benton County | 34 |
| 22 | Stevens County | 34 |
| 23 | Clallam County | 36 |
| 24 | Columbia County | 36 |
| 25 | Yakima County | 37 |
Source: EPA Air Quality Index annual summary (2024). All counties with data are ranked. Estimates carry margins of error.
Citing this page: GIS Map, “Counties with the Cleanest Air in Washington”, https://gismap.land/rankings/washington/cleanest-air-counties. Figures from EPA Air Quality Index annual summary (2024).
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