SmogRank / Spain / Basque Country / Beasain
Beasain, month by month
Beasain has a measured daily mean on 865 days since 14 February 2023. Its worst month was June 2025, at 58 US AQI (13.1 µg/m³), 647th of 2,508 cities on that month's world ranking. Its cleanest was January 2026, at 33 US AQI (6.0 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
18 months
| Month | Why |
|---|---|
| Oct 2026 | 6 of 11 days measured; a month needs 8. The others: 2 with no readings from the monitor, 3 with readings for part of the day (a day needs 18 hours). |
| Jul 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with readings for part of the day (a day needs 18 hours). |
| Jun 2026 | 7 of 30 days measured; a month needs 21. The others: 23 with readings for part of the day (a day needs 18 hours). |
| May 2026 | 2 of 31 days measured; a month needs 22. The others: 10 with no readings from the monitor, 19 with readings for part of the day (a day needs 18 hours). |
| Apr 2026 | No day measured. The others: 25 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Mar 2026 | No day measured. The others: 31 with no readings from the monitor. |
| Feb 2026 | 7 of 28 days measured; a month needs 20. The others: 19 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Aug 2025 | 16 of 31 days measured; a month needs 22. The others: 8 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours). |
| Oct 2024 | 10 of 31 days measured; a month needs 22. The others: 21 with readings for part of the day (a day needs 18 hours). |
| Sep 2024 | No day measured. The others: 3 with no readings from the monitor, 27 with readings for part of the day (a day needs 18 hours). |
| Aug 2024 | 7 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 23 with readings for part of the day (a day needs 18 hours). |
| Jul 2024 | 12 of 31 days measured; a month needs 22. The others: 19 with readings for part of the day (a day needs 18 hours). |
| Jun 2024 | 14 of 30 days measured; a month needs 21. The others: 16 with readings for part of the day (a day needs 18 hours). |
| Mar 2024 | 15 of 31 days measured; a month needs 22. The others: 10 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Jan 2024 | 15 of 31 days measured; a month needs 22. The others: 14 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Aug 2023 | 20 of 31 days measured; a month needs 22. The others: 2 with no readings from the monitor, 9 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 2 of 28 days measured; a month needs 20. The others: 13 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Beasain's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2025 | 5813.1 µg/m³ | 647thof 2,508 | Basque Country and Castille and León, Spain, June 2025 |
| November 2024 | 5812.8 µg/m³ | 518thof 2,624 | – |
| June 2023 | 5712.1 µg/m³ | 546thof 1,603 | – |
| February 2025 | 5511.2 µg/m³ | 1,078thof 2,633 | – |
| February 2024 | 5511.0 µg/m³ | 558thof 2,486 | Southern Europe, February 2024 Europe, 27 January to 2 February 2024 |
| December 2024 | 5410.9 µg/m³ | 774thof 2,616 | – |
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.
Beasain's worst days
| Day | US AQI | Episode |
|---|---|---|
| 5 Sept 2023 | 9633.5 µg/m³ | North-eastern Spain and France, September 2023 |
| 10 Jun 2025 | 9633.4 µg/m³ | Basque Country and Castille and León, Spain, June 2025 |
| 7 Feb 2024 | 8828.9 µg/m³ | Southern Europe, February 2024 |
| 31 Jan 2024 | 8426.7 µg/m³ | Europe, 27 January to 2 February 2024 |
| 13 Aug 2025 | 8125.1 µg/m³ | Spain, Portugal and Andorra, August 2025 |
| 12 Aug 2025 | 8024.8 µg/m³ | Spain, Portugal and Andorra, August 2025 |
| 4 Feb 2024 | 8024.5 µg/m³ | Southern Europe, February 2024 |
| 24 Jun 2025 | 7923.9 µg/m³ | – |
| 18 Oct 2025 | 7923.9 µg/m³ | – |
| 20 Jun 2023 | 7823.8 µg/m³ | – |
Daily means, the highest since 14 Feb 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, Beasain, Spain, 14 Feb 2023 – 9 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/es/beasain/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.
Beasain 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).