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AirHistory

Air Quality in Washington

10-year air quality trends for 30 monitored areas in Washington.

See full Washington air quality rankings →
30
Cities
31
Avg AQI (5yr)
16
Improving
3
Stable
11
Worsening

All Monitored Areas in Washington

Garfield, Washington

Garfield County · AQI 20 (5yr avg) · Improving · PM2.5

A

Cowlitz, Washington

Cowlitz County · AQI 22 (5yr avg) · Improving · PM2.5

B

Skagit, Washington

Skagit County · AQI 28 (5yr avg) · Improving · PM2.5

B

Jefferson, Washington

Jefferson County · AQI 22 (5yr avg) · Improving · PM2.5

B

Adams, Washington

Adams County · AQI 18 (5yr avg) · Improving · PM2.5

B

Mason, Washington

Mason County · AQI 24 (5yr avg) · Improving · PM2.5

B

Thurston, Washington

Thurston County · AQI 27 (5yr avg) · Improving · PM2.5

B

Grays Harbor, Washington

Grays Harbor County · AQI 25 (5yr avg) · Improving · PM2.5

B

Lewis, Washington

Lewis County · AQI 25 (5yr avg) · Improving · PM2.5

B

Franklin, Washington

Franklin County · AQI 22 (5yr avg) · Stable · PM2.5

B

Klickitat, Washington

Klickitat County · AQI 22 (5yr avg) · Stable · PM2.5

B

Whatcom, Washington

Whatcom County · AQI 29 (5yr avg) · Improving · PM2.5

B

Whitman, Washington

Whitman County · AQI 23 (5yr avg) · Stable · PM2.5

B

Clallam, Washington

Clallam County · AQI 37 (5yr avg) · Improving · PM2.5

B

Clark, Washington

Clark County · AQI 34 (5yr avg) · Stable · PM2.5

B

Grant, Washington

Grant County · AQI 26 (5yr avg) · Stable · PM2.5

B

Kitsap, Washington

Kitsap County · AQI 25 (5yr avg) · Worsening · PM2.5

B

Walla Walla, Washington

Walla Walla County · AQI 25 (5yr avg) · Worsening · PM2.5

B

Kittitas, Washington

Kittitas County · AQI 28 (5yr avg) · Worsening · PM2.5

B

Spokane, Washington

Spokane County · AQI 41 (5yr avg) · Improving · PM2.5

B

Chelan, Washington

Chelan County · AQI 32 (5yr avg) · Stable · PM2.5

C

King, Washington

King County · AQI 45 (5yr avg) · Improving · PM2.5

C

Pierce, Washington

Pierce County · AQI 43 (5yr avg) · Stable · Ozone

C

Snohomish, Washington

Snohomish County · AQI 38 (5yr avg) · Stable · PM2.5

C

Benton, Washington

Benton County · AQI 38 (5yr avg) · Worsening · PM2.5

C

Stevens, Washington

Stevens County · AQI 42 (5yr avg) · Worsening · PM2.5

C

Columbia, Washington

Columbia County · AQI 32 (5yr avg) · Worsening · PM2.5

C

Okanogan, Washington

Okanogan County · AQI 49 (5yr avg) · Worsening · PM2.5

C

Yakima, Washington

Yakima County · AQI 49 (5yr avg) · Worsening · PM2.5

C

Asotin, Washington

Asotin County · AQI 43 (5yr avg) · Worsening · PM2.5

D
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Frequently Asked Questions

Washington has 30 monitored areas with an average 5-year AQI of 31 and an average Air Quality Grade of B. 16 cities are improving, 11 are worsening, and 3 are stable.

Garfield, Washington has the best Air Quality Grade (A) in Washington with a 5-year average AQI of 20.

Of 30 monitored areas in Washington, 16 are showing improving trends, 11 are worsening, and 3 remain stable over the past decade.

Sources: EPA Air Quality System (AQS)
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