SmogRank / United Kingdom / England / Derby
Derby, month by month
Derby has a measured daily mean on 326 days since 30 March 2025. Its worst month was March 2026, at 55 US AQI (11.0 µg/m³), 1,423rd of 2,971 cities on that month's world ranking. Its cleanest was September 2025, at 28 US AQI (5.1 µg/m³).
Every month since 2025
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
8 months
| Month | Why |
|---|---|
| Sep 2026 | 1 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jun 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Mar 2025 | 2 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.
Derby's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| March 2026 | 5511.0 µg/m³ | 1,423rdof 2,971 | Europe, 1 to 12 March 2026 |
| April 2025 | 5310.2 µg/m³ | 1,125thof 2,951 | – |
| January 2026 | 529.4 µg/m³ | 1,173rdof 2,617 | Europe, January and February 2026 |
| February 2026 | 519.2 µg/m³ | 1,620thof 2,866 | Europe, January and February 2026 |
| October 2025 | 458.1 µg/m³ | 845thof 2,614 | – |
| December 2025 | 427.6 µg/m³ | 1,959thof 3,006 | – |
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.
Derby's worst days
| Day | US AQI | Episode |
|---|---|---|
| 9 Mar 2026 | 9633.3 µg/m³ | Europe, 1 to 12 March 2026 |
| 3 Feb 2026 | 8628.1 µg/m³ | Europe, January and February 2026 |
| 5 Mar 2026 | 8225.8 µg/m³ | Europe, 1 to 12 March 2026 |
| 26 Jan 2026 | 8225.7 µg/m³ | Europe, January and February 2026 |
| 21 Mar 2026 | 7823.4 µg/m³ | – |
| 27 Apr 2025 | 7723.0 µg/m³ | – |
| 4 Feb 2026 | 7522.1 µg/m³ | Europe, January and February 2026 |
| 5 Feb 2026 | 7521.9 µg/m³ | Europe, January and February 2026 |
| 20 Mar 2026 | 7421.5 µg/m³ | – |
| 23 Dec 2025 | 7421.3 µg/m³ | – |
Daily means, the highest since 30 Mar 2025; 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, Derby, United Kingdom, 30 Mar 2025 – 11 Oct 2026. Monitor data from UK-AIR (Defra), read from the publisher; sources listed at smogrank.com/sources. smogrank.com/gb/derby/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.
Derby now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).