SmogRank / World / Europe / Spain / Castille and León
Most polluted cities in Castille and León, Spain
1 measured city, last 30 days; 0 above the WHO 24-hour guideline. The only one: San Ildefonso at 6.3 µg/m³, #1,640 in the world.
26 monitors in Spain stopped reporting on 6 Oct, 05:00 Madrid time. Cities that rely on them are missing from the 24-hour board and may drop from the longer ones; that isn't clean air, and they return when the data does.
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.
Cities coloured by their PM2.5 over the last 24 hours. Fires, smoke and ash: Oct 5, the newest UTC day mapped.
- 1San Ildefonso 0%
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
Estimated: cities without a monitor
Castille and León cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Zamora | ≈ 6 µg/m³ |
| Ávila | ≈ 5 µg/m³ |
| Segovia | ≈ 6 µg/m³ |
| San Andrés del Rabanedo | ≈ 6 µg/m³ |
| Laguna de Duero | ≈ 6 µg/m³ |
| Benavente | ≈ 6 µg/m³ |
| Villaquilambre | ≈ 6 µg/m³ |
| Béjar | ≈ 5 µg/m³ |
Bad-air episodes in Castille and León
- Galicia, Asturias and Castille and León, Spain, June 202624 June 2026, 1 day8 cities60 µg/m³peak, A Coruña
- Northern Spain, August 202526 to 27 August 2025, 2 days15 cities61 µg/m³peak, León
- Spain, Portugal and Andorra, August 202510 to 22 August 2025, 13 days57 cities203 µg/m³peak, Ponferrada
- Basque Country and Castille and León, Spain, June 202510 June 2025, 1 day9 cities33 µg/m³peak, Beasain
- Northern Spain, October 202430 to 31 October 2024, 2 days29 cities49 µg/m³peak, Villarejo de Salvanés
- Spain, Portugal and France, February 20241 to 2 February 2024, 2 days20 cities42 µg/m³peak, Vigo
Times when many cities around here had PM2.5 at twice their usual or more on the same days.
Use this board
SmogRank, most polluted cities in Castille and León, Spain, PM2.5, last 30 days to 6 Oct 2026, 23:00 UTC, smogrank.com/es/region/castille-and-leon?w=30d.
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.
Updated 2026-10-06 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.