SmogRank / United States / California / Red Bluff
Red Bluff, month by month
Red Bluff has a measured daily mean on 1,206 days since 4 January 2023. Its worst month was August 2023, at 56 US AQI (11.6 µg/m³), 386th of 1,980 cities on that month's world ranking. Its cleanest was March 2024, at 18 US AQI (3.3 µg/m³). 2025 averaged 34 US AQI (6.2 µg/m³), against 36 US AQI (6.5 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
7 months
| Month | Why |
|---|---|
| Dec 2025 | 19 of 31 days measured; a month needs 22. The others: 6 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Nov 2025 | 14 of 30 days measured; a month needs 21. The others: 12 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours). |
| May 2023 | 18 of 31 days measured; a month needs 22. The others: 8 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Apr 2023 | 9 of 30 days measured; a month needs 21. The others: 17 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours), 3 missing from OpenAQ's archive. |
| Mar 2023 | 10 of 31 days measured; a month needs 22. The others: 1 with readings for part of the day (a day needs 18 hours), 20 missing from OpenAQ's archive. |
| Feb 2023 | 1 of 28 days measured; a month needs 20. The others: 2 with readings for part of the day (a day needs 18 hours), 25 missing from OpenAQ's archive. |
| Jan 2023 | 20 of 31 days measured; a month needs 22. The others: 2 with readings for part of the day (a day needs 18 hours), 6 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Red Bluff's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| August 2023 | 5611.6 µg/m³ | 386thof 1,980 | North-western United States and Canada, August 2023 |
| July 2024 | 5511.2 µg/m³ | 540thof 2,566 | California and Nevada, United States, July 2024 |
| August 2024 | 529.8 µg/m³ | 653rdof 2,010 | – |
| July 2025 | 529.7 µg/m³ | 1,338thof 2,889 | – |
| July 2023 | 529.6 µg/m³ | 700thof 1,432 | – |
| October 2024 | 488.6 µg/m³ | 687thof 2,020 | – |
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.
Red Bluff's worst days
| Day | US AQI | Episode |
|---|---|---|
| 29 Aug 2023 | 13649.6 µg/m³ | North-western United States and Canada, August 2023 |
| 27 Oct 2023 | 11842.4 µg/m³ | – |
| 14 Oct 2024 | 11641.7 µg/m³ | – |
| 31 Aug 2023 | 11641.4 µg/m³ | North-western United States and Canada, August 2023 |
| 11 Jul 2025 | 10436.9 µg/m³ | – |
| 12 Jul 2025 | 9934.7 µg/m³ | – |
| 3 Aug 2024 | 9432.1 µg/m³ | – |
| 28 Jul 2024 | 8628.0 µg/m³ | – |
| 30 Aug 2023 | 8225.6 µg/m³ | North-western United States and Canada, August 2023 |
| 4 Jul 2024 | 8225.5 µg/m³ | California and Nevada, United States, July 2024 |
Daily means, the highest since 4 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, Red Bluff, United States, 4 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/red-bluff/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.
Red Bluff now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 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).