SmogRank / United States / Oregon / Brookings
Brookings, month by month
Brookings has a measured daily mean on 1,254 days since 19 March 2023. Its worst month was September 2023, at 46 US AQI (8.3 µg/m³), 1,008th of 2,176 cities on that month's world ranking. Its cleanest was September 2026, at 11 US AQI (2.0 µg/m³). 2025 averaged 17 US AQI (3.1 µg/m³), against 18 US AQI (3.3 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 |
|---|---|
| Oct 2026 | 7 of 11 days measured; a month needs 8. The others: 3 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 9 of 31 days measured; a month needs 22. The others: 2 with readings for part of the day (a day needs 18 hours), 2 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Brookings's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| September 2023 | 468.3 µg/m³ | 1,008thof 2,176 | Oregon and California, United States, September 2023 |
| August 2023 | 417.4 µg/m³ | 1,177thof 1,980 | – |
| September 2025 | 274.8 µg/m³ | 2,690thof 3,104 | – |
| October 2024 | 234.1 µg/m³ | 1,922ndof 2,020 | – |
| October 2023 | 224.0 µg/m³ | 1,918thof 2,012 | – |
| July 2024 | 223.9 µg/m³ | 2,454thof 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.
Brookings's worst days
| Day | US AQI | Episode |
|---|---|---|
| 23 Sept 2023 | 10838.4 µg/m³ | Oregon and California, United States, September 2023 |
| 19 Sept 2023 | 8728.4 µg/m³ | – |
| 27 Aug 2023 | 7622.4 µg/m³ | – |
| 24 Aug 2023 | 7522.1 µg/m³ | – |
| 26 Aug 2023 | 6919.0 µg/m³ | – |
| 22 Sept 2023 | 6918.8 µg/m³ | – |
| 28 Aug 2023 | 6918.6 µg/m³ | – |
| 26 Sept 2025 | 6616.9 µg/m³ | – |
| 16 Sept 2023 | 6516.7 µg/m³ | – |
| 17 Sept 2023 | 6013.9 µg/m³ | – |
Daily means, the highest since 19 Mar 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, Brookings, United States, 19 Mar 2023 – 7 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/brookings-oregon/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.
Brookings 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).