SmogRank / World / United States / Washington / August 2026

Most polluted cities in Washington, United States, August 2026

56 cities in Washington, United States ranked by their average PM2.5 over the 31 days. Worst: Wenatchee at 44.6 µg/m³, #33 of 2,866 cities in the world. Cleanest: Port Townsend at 4.1. 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.

← Wenatchee 42% 40%0
Every city in Washington, United States ranked for August 2026, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Wenatchee
    42%
  2. 2Quincy
    39%
  3. 3Airway Heights
    35%
  4. 4Ephrata
    33%
  5. 5Mead
    32%
  6. 6Moses Lake
    32%
  7. 7Fairwood
    31%
  8. 8Liberty Lake
    27%
  9. 9Spokane Valley
    26%
  10. 10Spokane
    26%
  11. 11Cheney
    24%
  12. 12Union Gap
    21%
  13. 13Walla Walla
    19%
  14. 14Ellensburg
    19%
  15. 14Yakima
    19%
  16. 16Sunnyside
    17%
  17. 17Toppenish
    16%
  18. 18Redmondlow-cost sensors
    15%
  19. 19Union Hill-Novelty Hilllow-cost sensors
    14%
  20. 20Grandview
    13%
  21. 21Prosser
    13%
  22. 22Pullman
    13%
  23. 23Kirklandlow-cost sensors
    11%
  24. 24Finley
    10%
  25. 25North Creeklow-cost sensors
    10%
  26. 26Columbia Citylow-cost sensors
    10%
  27. 27North Bend
    10%
  28. 28Tri-Cities
    10%
  29. 29Inglewood-Finn Hilllow-cost sensors
    9%
  30. 30Kent
    7%
  31. 31Bothelllow-cost sensors
    7%
  32. 32Bellevue
    7%
  33. 33Vancouver
    6%
  34. 34Auburn
    6%
  35. 35Ridgefield
    6%
  36. 36Tacoma
    6%
  37. 37Parkland
    6%
  38. 38White Center
    3%
  39. 39Chehalis
    3%
  40. 40Renton
    3%
  41. 41Seattle
    0%
  42. 42Burien
    0%
  43. 42Shoreline
    0%
  44. 44Bremerton
    0%
  45. 44Tulalip
    0%
  46. 46Bellingham
    0%
  47. 47Longview
    0%
  48. 48Picnic Point-North Lynnwood
    0%
  49. 49Lacey
    0%
  50. 50Shelton
    0%
  51. 51Mount Vernon
    0%
  52. 52Port Angeles
    0%
  53. 53Lynden
    0%
  54. 54Aberdeen
    0%
  55. 54Anacortes
    0%
  56. 54Port Townsend
    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

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SmogRank, most polluted cities in Washington, United States, PM2.5, August 2026, smogrank.com/us/region/washington/history/2026-08 (accessed 6 Oct 2026).

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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.