SmogRank / United States / North Carolina / Durham
Durham, month by month
Durham has a measured daily mean on 1,288 days since 1 January 2023. Its worst month was June 2023, at 60 US AQI (13.8 µg/m³), 444th of 1,603 cities on that month's world ranking. Its cleanest was August 2025, at 26 US AQI (4.6 µg/m³). 2025 averaged 41 US AQI (7.4 µg/m³), against 52 US AQI (9.8 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 |
|---|---|
| Mar 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. |
| Dec 2023 | 14 of 31 days measured; a month needs 22. The others: 17 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.
Durham's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2023 | 6013.8 µg/m³ | 444thof 1,603 | Eastern United States and Canada, June and July 2023 Eastern United States and Canada, May and June 2023 |
| February 2024 | 5812.9 µg/m³ | 413thof 2,486 | – |
| April 2024 | 5511.4 µg/m³ | 813thof 2,520 | – |
| August 2024 | 5410.5 µg/m³ | 531stof 2,010 | – |
| January 2024 | 5310.3 µg/m³ | 851stof 2,385 | – |
| November 2023 | 5310.2 µg/m³ | 580thof 2,243 | – |
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.
Durham's worst days
| Day | US AQI | Episode |
|---|---|---|
| 30 Jun 2023 | 10537.2 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 18 Jul 2023 | 10436.8 µg/m³ | United States and Canada, July 2023 |
| 15 Mar 2024 | 8929.3 µg/m³ | Eastern United States, March 2024 |
| 25 Feb 2026 | 8527.3 µg/m³ | Eastern United States, February 2026 |
| 9 Jun 2023 | 8527.2 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 17 Jul 2023 | 8226.0 µg/m³ | United States and Canada, July 2023 |
| 7 Jun 2023 | 8024.7 µg/m³ | Eastern United States and Canada, May and June 2023 |
| 28 Jun 2023 | 8024.7 µg/m³ | Eastern United States and Canada, June and July 2023 |
| 22 Feb 2024 | 8024.6 µg/m³ | – |
| 23 Feb 2024 | 7924.1 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, Durham, 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/durham/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.
Durham 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).