SmogRank / United States / California / Redding
Redding, month by month
Redding has a measured daily mean on 1,309 days since 1 January 2023. Its worst month was August 2023, at 57 US AQI (12.3 µg/m³), 311th of 1,980 cities on that month's world ranking. Its cleanest was May 2024, at 21 US AQI (3.8 µg/m³). 2025 averaged 38 US AQI (6.8 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
1 month
| Month | Why |
|---|---|
| Mar 2024 | 14 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 16 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Redding's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| August 2023 | 5712.3 µg/m³ | 311thof 1,980 | North-western United States and Canada, August 2023 |
| December 2025 | 5511.0 µg/m³ | 1,131stof 3,006 | – |
| July 2025 | 5410.9 µg/m³ | 1,070thof 2,889 | – |
| December 2023 | 5410.8 µg/m³ | 566thof 2,247 | California and Oregon, United States, December 2023 |
| July 2024 | 5410.5 µg/m³ | 631stof 2,566 | – |
| January 2026 | 529.9 µg/m³ | 1,117thof 2,617 | – |
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.
Redding's worst days
| Day | US AQI | Episode |
|---|---|---|
| 13 Jul 2025 | 15460.3 µg/m³ | – |
| 29 Aug 2023 | 14352.5 µg/m³ | North-western United States and Canada, August 2023 |
| 17 Dec 2023 | 12745.9 µg/m³ | California and Oregon, United States, December 2023 |
| 31 Aug 2023 | 10938.6 µg/m³ | North-western United States and Canada, August 2023 |
| 10 Oct 2024 | 10637.4 µg/m³ | – |
| 11 Oct 2024 | 10035.2 µg/m³ | – |
| 28 Jul 2024 | 8929.5 µg/m³ | – |
| 27 Oct 2023 | 8728.6 µg/m³ | – |
| 29 Jul 2024 | 8326.3 µg/m³ | – |
| 12 Jul 2025 | 8225.6 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, Redding, 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/redding/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.
Redding 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).