SmogRank / United States / South Dakota / Brookings
Brookings, month by month
Brookings has a measured daily mean on 1,339 days since 11 January 2023. Its worst month was June 2025, at 63 US AQI (15.8 µg/m³), 380th of 2,508 cities on that month's world ranking. Its cleanest was September 2026, at 17 US AQI (3.1 µg/m³). 2025 averaged 52 US AQI (9.8 µg/m³), against 34 US AQI (6.2 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 |
|---|---|
| Jan 2023 | 21 of 31 days measured; a month needs 22. |
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 |
|---|---|---|---|
| June 2025 | 6315.8 µg/m³ | 380thof 2,508 | Northern United States and Canada, June 2025 Northern United States and Canada, May and June 2025 |
| September 2023 | 5611.9 µg/m³ | 335thof 2,176 | Northern United States, September 2023 Northern United States and Canada, August and September 2023 |
| June 2023 | 5611.7 µg/m³ | 574thof 1,603 | Eastern United States and Canada, June and July 2023 |
| July 2025 | 5511.5 µg/m³ | 942ndof 2,889 | North-eastern United States and Canada, 29 July to 9 August 2025 North-eastern United States and Canada, 24 to 28 July 2025and 1 more |
| August 2023 | 5511.4 µg/m³ | 407thof 1,980 | Northern United States and Canada, August and September 2023 Northern United States, August 2023and 1 more |
| October 2024 | 5511.2 µg/m³ | 436thof 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.
Brookings's worst days
| Day | US AQI | Episode |
|---|---|---|
| 15 Jul 2023 | 16271.6 µg/m³ | United States and Canada, July 2023 |
| 18 May 2023 | 15763.8 µg/m³ | Northern United States and Canada, May 2023 |
| 1 Jun 2025 | 15460.4 µg/m³ | Northern United States and Canada, May and June 2025 |
| 6 Sept 2023 | 14151.6 µg/m³ | Northern United States and Canada, August and September 2023 |
| 16 Jul 2023 | 13649.9 µg/m³ | United States and Canada, July 2023 |
| 1 Aug 2025 | 12645.7 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 31 Jul 2025 | 11440.8 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
| 31 May 2025 | 11239.9 µg/m³ | Northern United States and Canada, May and June 2025 |
| 12 Jun 2025 | 10236.1 µg/m³ | Northern United States and Canada, June 2025 |
| 2 Aug 2025 | 9834.4 µg/m³ | North-eastern United States and Canada, 29 July to 9 August 2025 |
Daily means, the highest since 11 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, Brookings, United States, 11 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/brookings/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 19:07 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).