SmogRank / United States / Missouri / Saint Joseph
Saint Joseph, month by month
Saint Joseph has a measured daily mean on 1,349 days since 1 January 2023. Its worst month was June 2023, at 59 US AQI (13.4 µg/m³), 461st of 1,603 cities on that month's world ranking. Its cleanest was September 2026, at 35 US AQI (6.3 µg/m³). 2025 averaged 52 US AQI (9.5 µg/m³), against 47 US AQI (8.4 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
Saint Joseph's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2023 | 5913.4 µg/m³ | 461stof 1,603 | – |
| September 2023 | 5913.4 µg/m³ | 243rdof 2,176 | Northern United States and Canada, August and September 2023 |
| June 2025 | 5812.9 µg/m³ | 675thof 2,508 | – |
| August 2025 | 5812.9 µg/m³ | 587thof 2,901 | North-eastern United States and Canada, 29 July to 9 August 2025 |
| July 2023 | 5611.6 µg/m³ | 448thof 1,432 | – |
| July 2024 | 5511.3 µg/m³ | 520thof 2,566 | – |
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.
Saint Joseph's worst days
| Day | US AQI | Episode |
|---|---|---|
| 1 Aug 2025 | 13348.6 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 7 Sept 2023 | 12143.8 µg/m³ | Northern United States and Canada, August and September 2023 |
| 6 Sept 2023 | 11139.7 µg/m³ | Northern United States and Canada, August and September 2023 |
| 14 Mar 2025 | 9432.1 µg/m³ | United States and Mexico, March 2025 |
| 2 Aug 2025 | 9030.3 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 24 Jan 2023 | 8326.3 µg/m³ | – |
| 18 Sept 2023 | 7823.5 µg/m³ | – |
| 16 Jul 2023 | 7823.4 µg/m³ | – |
| 14 May 2024 | 7823.4 µg/m³ | – |
| 13 Mar 2025 | 7823.4 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, Saint Joseph, 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/saint-joseph/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.
Saint Joseph now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).