SmogRank / Spain / Catalonia / Mollet del Vallès
Mollet del Vallès, month by month
Mollet del Vallès has a measured daily mean on 626 days since 5 October 2023. Its worst month was December 2023, at 83 US AQI (26.3 µg/m³), 85th of 2,247 cities on that month's world ranking. Its cleanest was September 2025, at 51 US AQI (9.2 µg/m³).
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
16 months
| Month | Why |
|---|---|
| Oct 2026 | No day measured. The others: 6 with no readings from the monitors, 5 with readings for part of the day (a day needs 18 hours). |
| Sep 2026 | No day measured. The others: 12 with no readings from the monitors, 18 with readings for part of the day (a day needs 18 hours). |
| 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. |
| Mar 2026 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Feb 2026 | No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 5 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks. |
| Jan 2025 | 13 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Oct 2024 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 6 of 31 days measured; a month needs 22. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Jul 2024 | 12 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 15 of 31 days measured; a month needs 22. The others: 16 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.
Mollet del Vallès's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2023 | 8326.3 µg/m³ | 85thof 2,247 | Spain, France and 2 more countries, December 2023 to January 2024 France, Spain and Germany, December 2023 |
| February 2025 | 7923.9 µg/m³ | 311thof 2,633 | – |
| January 2024 | 7823.5 µg/m³ | 203rdof 2,385 | Europe, 27 January to 2 February 2024 Europe, 8 to 27 January 2024and 1 more |
| February 2024 | 6818.4 µg/m³ | 238thof 2,486 | Europe, 27 January to 2 February 2024 |
| August 2025 | 6717.8 µg/m³ | 249thof 2,901 | Spain, Portugal and Andorra, August 2025 |
| June 2025 | 6717.7 µg/m³ | 290thof 2,508 | North-eastern Spain, June 2025 |
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.
Mollet del Vallès's worst days
| Day | US AQI | Episode |
|---|---|---|
| 29 Dec 2023 | 14453.1 µg/m³ | Spain, France and 2 more countries, December 2023 to January 2024 |
| 30 Dec 2023 | 12645.6 µg/m³ | Spain, France and 2 more countries, December 2023 to January 2024 |
| 28 Jan 2024 | 11541.1 µg/m³ | Europe, 27 January to 2 February 2024 |
| 1 Jan 2024 | 11440.6 µg/m³ | Spain, France and 2 more countries, December 2023 to January 2024 |
| 20 Dec 2023 | 11240.0 µg/m³ | – |
| 26 Dec 2023 | 11240.0 µg/m³ | Spain, France and 2 more countries, December 2023 to January 2024 |
| 25 Jan 2024 | 11240.0 µg/m³ | Europe, 8 to 27 January 2024 |
| 19 Dec 2023 | 11139.5 µg/m³ | France, Spain and Germany, December 2023 |
| 7 Feb 2024 | 11039.1 µg/m³ | – |
| 25 Dec 2023 | 10938.7 µg/m³ | Spain, France and 2 more countries, December 2023 to January 2024 |
Daily means, the highest since 5 Oct 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, Mollet del Vallès, Spain, 5 Oct 2023 – 21 Jan 2026. Monitor data from EEA and Catalonia Medi Ambient I Sostenibilitat, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/es/mollet-del-valles/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.
Mollet del Vallès 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).