SmogRank / United States / Wyoming / Lander
Lander, month by month
Lander, Wyoming has a measured daily mean on 1,294 days since 1 January 2023. Its worst month was January 2023, at 59 US AQI (13.2 µg/m³), 302nd of 1,261 cities on that month's world ranking. Its cleanest was September 2026, at 8 US AQI (1.5 µg/m³). 2025 averaged 33 US AQI (6.0 µg/m³), against 42 US AQI (7.5 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
2 months
| Month | Why |
|---|---|
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Lander's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2023 | 5913.2 µg/m³ | 302ndof 1,261 | – |
| January 2025 | 5712.1 µg/m³ | 718thof 2,474 | – |
| October 2024 | 5611.7 µg/m³ | 406thof 2,020 | North-western United States, October 2024 |
| January 2024 | 5511.5 µg/m³ | 742ndof 2,385 | – |
| December 2023 | 519.2 µg/m³ | 894thof 2,247 | – |
| May 2023 | 519.1 µg/m³ | 629thof 1,600 | North-western United States and Canada, May 2023 |
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.
Lander's worst days
| Day | US AQI | Episode |
|---|---|---|
| 6 Oct 2024 | 15256.4 µg/m³ | North-western United States, October 2024 |
| 4 Jul 2026 | 13850.7 µg/m³ | – |
| 5 Oct 2024 | 13047.1 µg/m³ | – |
| 19 May 2023 | 9934.6 µg/m³ | North-western United States and Canada, May 2023 |
| 4 Jul 2023 | 9331.8 µg/m³ | – |
| 24 Aug 2025 | 9130.6 µg/m³ | – |
| 3 Aug 2026 | 8829.0 µg/m³ | North-western United States and Canada, July and August 2026 |
| 27 Jan 2025 | 8226.0 µg/m³ | – |
| 15 Oct 2024 | 8024.7 µg/m³ | – |
| 18 May 2023 | 7823.8 µg/m³ | – |
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, Lander, Wyoming, United States, 1 Jan 2023 – 10 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/lander/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.
Lander 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).