SmogRank / World / Spain / Basque Country / October 2025

Most unhealthy days in Basque Country, Spain, October 2025

14 cities in Basque Country, Spain ranked by their share of unhealthy days over the 31 days. The most unhealthy days: Beasain, Spain, 0 of 25 measured days. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Beasain 0% 0.75%0
Every city in Basque Country, Spain ranked for October 2025, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Beasain
    0 of 25
  2. 2Bilbao
    0 of 24
  3. 3Gasteiz / Vitoria
    0 of 25
  4. 3Oria
    0 of 23
  5. 3Amorebieta
    0 of 23
  6. 6Durango
    0 of 22
  7. 7Getxo
    0 of 22
  8. 8Laudio / Llodio
    0 of 25
  9. 8Azpeitia
    0 of 25
  10. 10Hernani
    0 of 24
  11. 11Tolosa
    0 of 22
  12. 12Donostia / San Sebastián
    0 of 25
  13. 13Zierbena
    0 of 24
  14. 14Bermeo
    0 of 22
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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

All cities in the world, October 2025 · All cities in Spain, October 2025 · Basque Country now

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SmogRank, most polluted cities in Basque Country, Spain, by unhealthy days, PM2.5, October 2025, smogrank.com/es/region/basque-country/history/2025-10?by=days (accessed 7 Oct 2026).

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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.