SmogRank / United States / Arkansas / Fort Smith
Fort Smith, month by month
Fort Smith has a measured daily mean on 1,181 days since 1 January 2023. Its worst month was March 2024, at 52 US AQI (9.9 µg/m³), 426th of 1,698 cities on that month's world ranking. Its cleanest was May 2026, at 26 US AQI (4.6 µg/m³). 2025 averaged 37 US AQI (6.6 µg/m³), against 42 US AQI (7.6 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
4 months
| Month | Why |
|---|---|
| May 2025 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| 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.
Fort Smith's worst months
| Month | US AQI | World rank |
|---|---|---|
| March 2024 | 529.9 µg/m³ | 426thof 1,698 |
| June 2023 | 529.8 µg/m³ | 821stof 1,603 |
| February 2024 | 529.7 µg/m³ | 710thof 2,486 |
| July 2023 | 529.4 µg/m³ | 720thof 1,432 |
| April 2023 | 519.3 µg/m³ | 545thof 1,622 |
| May 2023 | 519.3 µg/m³ | 585thof 1,600 |
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.
Fort Smith's worst days
| Day | US AQI | Episode |
|---|---|---|
| 14 Mar 2025 | 12545.3 µg/m³ | United States and Mexico, March 2025 |
| 20 Mar 2026 | 11641.4 µg/m³ | – |
| 1 Aug 2024 | 9733.9 µg/m³ | Southern and eastern United States and Mexico, July and August 2024 |
| 13 Apr 2023 | 9331.4 µg/m³ | – |
| 28 Jan 2026 | 9029.8 µg/m³ | Central United States, January 2026 |
| 29 Jan 2026 | 8728.5 µg/m³ | Central United States, January 2026 |
| 20 Feb 2024 | 8728.4 µg/m³ | – |
| 29 Mar 2023 | 7924.0 µg/m³ | – |
| 25 Feb 2024 | 7320.7 µg/m³ | – |
| 26 Feb 2024 | 7119.8 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, Fort Smith, 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/fort-smith/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.
Fort Smith 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).