SmogRank / United States / Washington / Ellensburg
Ellensburg, month by month
Ellensburg has a measured daily mean on 1,341 days since 1 January 2023. Its worst month was August 2026, at 76 US AQI (22.4 µg/m³), 197th of 2,896 cities on that month's world ranking. Its cleanest was May 2024, at 5 US AQI (0.9 µg/m³). 2025 averaged 34 US AQI (6.1 µg/m³), against 26 US AQI (4.6 µg/m³) in 2024.
Every month since 2023
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
Months without a mean, and why
1 month
| Month | Why |
|---|---|
| Nov 2025 | 16 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Ellensburg's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| August 2026 | 7622.4 µg/m³ | 197thof 2,896 | North-western United States and Canada, 4 to 22 August 2026 North-western United States and Canada, July and August 2026 |
| August 2023 | 6717.9 µg/m³ | 156thof 1,980 | North-western United States and Canada, August 2023 |
| September 2025 | 5913.5 µg/m³ | 388thof 3,104 | North-western United States and Canada, September 2025 North-western Canada and United States, September 2025and 1 more |
| January 2026 | 5310.3 µg/m³ | 1,054thof 2,617 | Washington, United States, January 2026 |
| November 2023 | 498.9 µg/m³ | 889thof 2,243 | – |
| January 2025 | 498.9 µg/m³ | 1,205thof 2,474 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Ellensburg's worst days
Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Ellensburg, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/ellensburg/history (accessed 12 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.
Ellensburg now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).