SmogRank / United States / South Dakota / Rapid City
Rapid City, month by month
Rapid City has a measured daily mean on 1,277 days since 1 January 2023. Its worst month was July 2024, at 64 US AQI (16.2 µg/m³), 151st of 2,566 cities on that month's world ranking. Its cleanest was March 2025, at 23 US AQI (4.2 µg/m³). 2025 averaged 34 US AQI (6.2 µg/m³), against 42 US AQI (7.5 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
5 months
| Month | Why |
|---|---|
| May 2026 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Apr 2026 | 15 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 21 of 31 days measured; a month needs 22. The others: 10 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.
Rapid City's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2024 | 6416.2 µg/m³ | 151stof 2,566 | North-western United States and Canada, July 2024 |
| September 2023 | 6114.3 µg/m³ | 201stof 2,176 | Northern United States and Canada, August and September 2023 North-western Canada and United States, September 2023 |
| May 2023 | 6013.7 µg/m³ | 176thof 1,600 | North-western United States and Canada, May 2023 Northern United States and Canada, May 2023 |
| August 2026 | 5511.5 µg/m³ | 622ndof 2,896 | North-western United States and Canada, July and August 2026 |
| August 2023 | 5410.8 µg/m³ | 474thof 1,980 | Northern United States and Canada, August and September 2023 |
| September 2024 | 5310.0 µg/m³ | 450thof 2,010 | North-western United States and Canada, 10 to 11 September 2024 |
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.
Rapid City's worst days
| Day | US AQI | Episode |
|---|---|---|
| 18 May 2023 | 17590.2 µg/m³ | Northern United States and Canada, May 2023 |
| 5 Sept 2023 | 16473.6 µg/m³ | Northern United States and Canada, August and September 2023 |
| 6 Sept 2023 | 15967.6 µg/m³ | Northern United States and Canada, August and September 2023 North-western Canada and United States, September 2023 |
| 16 Jul 2023 | 15055.4 µg/m³ | United States and Canada, July 2023 |
| 17 Jul 2023 | 14151.6 µg/m³ | United States and Canada, July 2023 North-western Canada and United States, July 2023 |
| 21 Jul 2024 | 13549.2 µg/m³ | North-western United States and Canada, July 2024 |
| 15 Jul 2023 | 13047.1 µg/m³ | United States and Canada, July 2023 |
| 22 Jul 2024 | 12946.8 µg/m³ | North-western United States and Canada, July 2024 |
| 24 Aug 2023 | 11139.5 µg/m³ | – |
| 17 May 2023 | 9934.9 µg/m³ | Northern United States and Canada, May 2023 |
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, Rapid City, 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/rapid-city/history (accessed 13 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.
Rapid City now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 00:07 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).