SmogRank / World / Spain / Basque Country / April 2023

Most unhealthy days in Basque Country, Spain, April 2023

9 cities in Basque Country, Spain ranked by their share of unhealthy days over the 30 days. The most unhealthy days: Gasteiz / Vitoria, Spain, 0 of 30 measured days. A city needs measurements on 70% of the days to be ranked.

OpenAQ's archive, where our readings come from, has almost none for 3 of these 30 days. Cities in the United States and Europe have them from the EPA's and the European Environment Agency's own records of the same monitors; elsewhere a city's average is over its other days. Why.

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.

← Gasteiz / Vitoria 0% 0.75%0
Every city in Basque Country, Spain ranked for April 2023, 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. 1Gasteiz / Vitoria
    0 of 30
  2. 2Beasain
    0 of 27
  3. 3Bilbao
    0 of 30
  4. 4Laudio / Llodio
    0 of 28
  5. 5Zalla
    0 of 27
  6. 6Azpeitia
    0 of 27
  7. 7Donostia / San Sebastián
    0 of 30
  8. 8Bermeo
    0 of 30
  9. 9Zarautz
    0 of 30
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, April 2023 · All cities in Spain, April 2023 · Basque Country now

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SmogRank, most polluted cities in Basque Country, Spain, by unhealthy days, PM2.5, April 2023, smogrank.com/es/region/basque-country/history/2023-04?by=days (accessed 8 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.