SmogRank / World / North America / United States / Washington

Most polluted cities in Washington, United States

48 measured cities, this year; 29 above the WHO annual guideline. Worst: Wenatchee at 10.4 µg/m³, #902 in the world.

About 20.4K people in these 11 cities breathed unhealthy air on an average day so far this year.

Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.

Washington: 48 measured citiesIdaho: 10 measured citiesMontana: 10 measured citiesOregon: 43 measured cities#48 Anacortes: 2.7 µg/m³#47 Mount Vernon: 2.9 µg/m³#46 Bellevue: 3.6 µg/m³#44 Aberdeen: 3.7 µg/m³#45 Bothell: 3.7 µg/m³#42 Port Townsend: 4.1 µg/m³#43 Union Hill-Novelty Hill: 4.1 µg/m³#41 Shelton: 4.4 µg/m³#39 Kirkland: 4.5 µg/m³#40 Longview: 4.5 µg/m³#36 Burien: 4.6 µg/m³#37 North Bend: 4.6 µg/m³#38 Ridgefield: 4.6 µg/m³#35 Lacey: 4.7 µg/m³#31 Bremerton: 4.9 µg/m³#32 Chehalis: 4.9 µg/m³#33 Kent: 4.9 µg/m³#34 Lynden: 4.9 µg/m³#30 Shoreline: 5.0 µg/m³#29 Columbia City: 5.3 µg/m³#27 Parkland: 5.4 µg/m³#28 Picnic Point-North Lynnwood: 5.4 µg/m³#25 Bellingham: 5.6 µg/m³#26 Port Angeles: 5.6 µg/m³#24 Pullman: 6.0 µg/m³#23 Seattle: 6.2 µg/m³#22 Renton: 6.3 µg/m³#21 Auburn: 6.5 µg/m³#19 Prosser: 6.7 µg/m³#20 Tacoma: 6.7 µg/m³#18 White Center: 6.8 µg/m³#16 Grandview: 7.1 µg/m³#17 Tri-Cities: 7.1 µg/m³#15 Ellensburg: 7.4 µg/m³#14 Quincy: 7.6 µg/m³#12 Liberty Lake: 7.7 µg/m³#13 Vancouver: 7.7 µg/m³#10 Airway Heights: 7.8 µg/m³#11 Ephrata: 7.8 µg/m³#9 Toppenish: 7.9 µg/m³#8 Walla Walla: 8.2 µg/m³#7 Yakima: 8.4 µg/m³#5 Mead: 8.5 µg/m³#6 Sunnyside: 8.5 µg/m³#4 Moses Lake: 8.6 µg/m³#3 Spokane: 8.7 µg/m³#2 Spokane Valley: 9.3 µg/m³#1 Wenatchee: 10.4 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Spokane 8.25K 8K0
Every measured city in Washington, United States with monitors in two or more places, one column each, ranked by people breathing unhealthy air: height is people on an average day, colour its average. Point at it to read a city; tap to open it.
  1. 1Spokane 8.25K
  2. 2Spokane Valley 3.27K
  3. 3Tri-Cities 2.67K
  4. 4Yakima 2.07K
  5. 5Wenatchee 1.69K
  6. 6Kirklandlow-cost sensors 1.23K
  7. 7Bothelllow-cost sensors 387
  8. 8Mead 316
  9. 9Union Hill-Novelty Hilllow-cost sensors 308
  10. 10Toppenish 162
  11. 11Seattle 0

Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.

Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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

Estimated: cities without a monitor

Washington cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Everett≈ 6 µg/m³Good
Federal Way≈ 7 µg/m³Good
Kennewick≈ 4 µg/m³Good
Pasco≈ 4 µg/m³Good
Marysville≈ 5 µg/m³Good
Lakewood≈ 7 µg/m³Good
Olympia≈ 6 µg/m³Good
Richland≈ 4 µg/m³Good
South Hill≈ 7 µg/m³Good
Sammamish≈ 8 µg/m³Good
City of Sammamish≈ 8 µg/m³Good
Edmonds≈ 7 µg/m³Good
Puyallup≈ 7 µg/m³Good
Lynnwood≈ 7 µg/m³Good
West Lake Sammamish≈ 8 µg/m³Good
University Place≈ 7 µg/m³Good
Des Moines≈ 6 µg/m³Good
Lake Stevens≈ 5 µg/m³Good
East Hill-Meridian≈ 8 µg/m³Good
SeaTac≈ 6 µg/m³Good
Spanaway≈ 7 µg/m³Good
Maple Valley≈ 4 µg/m³Good
Mercer Island≈ 6 µg/m³Good
Bainbridge Island≈ 6 µg/m³Good
Graham≈ 7 µg/m³Good
Cottage Lake≈ 8 µg/m³Good
Kenmore≈ 6 µg/m³Good
Camas≈ 4 µg/m³Good
Mukilteo≈ 6 µg/m³Good
West Lake Stevens≈ 5 µg/m³Good
Mountlake Terrace≈ 6 µg/m³Good
Silver Firs≈ 5 µg/m³Good
Eastmont≈ 5 µg/m³Good
Mill Creek≈ 7 µg/m³Good
Tukwila≈ 6 µg/m³Good
Bonney Lake≈ 4 µg/m³Good
Salmon Creek≈ 4 µg/m³Good
Orchards≈ 4 µg/m³Good
Hazel Dell≈ 4 µg/m³Good
Battle Ground≈ 4 µg/m³Good

Bad-air episodes in Washington

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Washington, United States, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/us/region/washington?w=year.

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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.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.