SmogRank / World / United States / Washington / September 2023
Most polluted cities in Washington, United States, September 2023
46 cities in Washington, United States ranked by their average PM2.5 over the 30 days. Worst: Lynden at 7.9 µg/m³, #1,131 of 2,128 cities in the world. Cleanest: Enumclaw at 2.6. A city needs measurements on 70% of the days to be ranked.
Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.
- 1Lynden 0%
- 2Renton 0%
- 2Toppenish 0%
- 4Seattle 0%
- 5White Center 0%
- 6Prosser 0%
- 7Ephrata 0%
- 7Sunnyside 0%
- 9Moses Lake 0%
- 10Spokane 0%
- 11Parkland 0%
- 11Port Angeles 0%
- 11Shoreline 0%
- 11Tacoma 0%
- 15Auburn 0%
- 15Yakima 0%
- 17Bellingham 0%
- 18Quincy 0%
- 18Ridgefield 0%
- 20Pullman 0%
- 20Spokane Valley 0%
- 22Wenatchee 0%
- 23Walla Walla 0%
- 24Longview 0%
- 25Ellensburg 0%
- 26Chehalis 0%
- 26North Bend 0%
- 28Airway Heights 0%
- 28Mount Vernon 0%
- 28Shelton 0%
- 31Bremerton 0%
- 31Port Townsend 0%
- 33Bellevue 0%
- 33Vancouver 0%
- 35Aberdeen 0%
- 36Mead 0%
- 37Lacey 0%
- 38Tri-Cities 0%
- 39Anacortes 0%
- 40Issaquah 0%
- 41Cheney 0%
- 41Oak Harbor 0%
- 43Finley 0%
- 44Tulalip 0%
- 45Mill Plain 0%
- 46Enumclaw 0%
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
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SmogRank, most polluted cities in Washington, United States, PM2.5, September 2023, smogrank.com/us/region/washington/history/2023-09 (accessed 6 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.