SmogRank / United States / Washington / Cheney

Cheney, month by month

Cheney has a measured daily mean on 461 days since 7 May 2023. Its worst month was August 2023, at 84 US AQI (26.8 µg/m³), 66th of 1,980 cities on that month's world ranking. Its cleanest was May 2024, at 4 US AQI (0.7 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)70 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAug79#180Sep22#2,768Oct16#2,670
2025too few days for a mean (a year needs 256)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)163 days measured
Jan11#2,378Feb10#2,478Mar5#1,697Apr4#2,520May4#2,684Jun5#2,563JulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)228 days measured
JanFebMarAprMay24#1,490Jun17#1,565Jul17#1,396Aug84#66Sep18#2,144Oct19#1,964Nov41#1,350Dec16#2,208
Each square is a month's mean PM2.5 in US AQI from Cheney's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Cheney marked; each year, the year's. A dashed square is the running month, so far.
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

Months without a mean, and why

25 months
MonthWhy
Jul 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured.
Nov 2025No day measured.
Oct 2025No day measured.
Sep 2025No day measured.
Aug 2025No day measured.
Jul 2025No day measured.
Jun 2025No day measured.
May 2025No day measured.
Apr 2025No day measured.
Mar 2025No day measured.
Feb 2025No day measured.
Jan 2025No day measured.
Dec 2024No day measured. The others: 31 with no readings from the monitor.
Nov 2024No day measured. The others: 30 with no readings from the monitor.
Oct 2024No day measured. The others: 31 with no readings from the monitor.
Sep 2024No day measured. The others: 30 with no readings from the monitor.
Aug 2024No day measured. The others: 31 with no readings from the monitor.
Jul 2024No day measured. The others: 31 with no readings from the monitor.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Cheney's worst months

MonthUS AQIDays measuredWorld rankEpisode
August 2023 8426.8 µg/m³28 of 3166thof 1,980North-western United States and Canada, August 2023
August 2026 7923.9 µg/m³29 of 31180thof 2,896North-western United States and Canada, 4 to 22 August 2026
North-western United States and Canada, July and August 2026
November 2023 417.3 µg/m³30 of 301,350thof 2,243–
May 2023 244.4 µg/m³23 of 311,490thof 1,600–
September 2026 223.9 µg/m³30 of 302,768thof 2,981–
October 2023 193.4 µg/m³30 of 311,964thof 2,012–

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.

Cheney's worst days

DayUS AQIEpisode
20 Aug 2023 378264.0 µg/m³North-western United States and Canada, August 2023
19 Aug 2023 360255.0 µg/m³North-western United States and Canada, August 2023
3 Aug 2026 17285.8 µg/m³North-western United States and Canada, July and August 2026
8 Aug 2026 15966.5 µg/m³North-western United States and Canada, 4 to 22 August 2026
4 Aug 2026 15459.5 µg/m³North-western United States and Canada, 4 to 22 August 2026
North-western United States and Canada, July and August 2026
9 Aug 2026 14854.4 µg/m³North-western United States and Canada, 4 to 22 August 2026
6 Aug 2026 14553.4 µg/m³North-western United States and Canada, 4 to 22 August 2026
7 Aug 2026 12344.4 µg/m³North-western United States and Canada, 4 to 22 August 2026
5 Aug 2026 12244.1 µg/m³North-western United States and Canada, 4 to 22 August 2026
21 Aug 2023 11641.5 µg/m³North-western United States and Canada, August 2023

Daily means, the highest since 7 May 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, Cheney, United States, 7 May 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/cheney/history (accessed 12 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.

Cheney now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 17:07 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).