Short answer. Check the National Air Quality Index (ICA) published by the Ministry for the Ecological Transition (MITECO) 12. It rates each monitoring station in six categories, from "buena" (good) to "extremadamente desfavorable" (extremely unfavourable), based on up to five pollutants 1. When it reads "desfavorable" (unfavourable), the official advice for the general population is to consider reducing prolonged and strenuous outdoor activity 1.
Where can I check air quality right now?
On MITECO's ICA viewer 2. By default it shows the latest available hour, and you can filter by station type: traffic, industrial or background stations 1. The data are provisional and not validated 1. Stations missing some pollutants appear as a translucent circle, and black dots mark stations with no data received 1.
What do the index levels mean?
The ICA uses PM10, PM2.5, ozone, nitrogen dioxide and sulphur dioxide; the worst pollutant sets the station's category 1. Ozone uses an 8-hour moving average and particles a 24-hour moving average 1. For PM2.5, "buena" is 0-10 µg/m³, "razonablemente buena" 11-20, "regular" 21-25, "desfavorable" 26-50, "muy desfavorable" 51-75 and "extremadamente desfavorable" 76-800 1.
| Category | Official advice, general population 1 | Official advice, sensitive groups 1 |
|---|---|---|
| Regular | Enjoy outdoor activities normally, but watch for symptoms such as coughing, sore throat, shortness of breath, excessive fatigue or palpitations | Consider reducing prolonged and strenuous outdoor activity; people with asthma or respiratory diseases should follow their medication plan carefully, and people with heart problems may notice palpitations, difficulty breathing or unusual fatigue |
| Desfavorable | Consider reducing prolonged and strenuous outdoor activity, especially with coughing, shortness of breath or sore throat | Consider reducing outdoor activity, moving it indoors or postponing it; follow your medical treatment plan meticulously |
| Muy desfavorable | Consider reducing outdoor activity, moving it indoors or postponing it | Reduce all outdoor activity; follow your medical treatment plan meticulously |
| Extremadamente desfavorable | Reduce all outdoor activity; use suitable protection for work that must be done outdoors | Avoid staying outdoors for long; go to an emergency service if your condition worsens |
Sensitive groups include adults and children with respiratory problems and adults with heart conditions 1. The index reflects short-term air quality, not the annual situation 1. See Air quality index explained.
How polluted is the air on average?
The population-weighted median of Spanish cities shows about 10 µg/m³ of PM2.5 (annual mean 2021-2023) 3, twice the WHO guideline of 5 µg/m³ 5. Nitrogen dioxide is about 7.7 µg/m³ 4, below the WHO guideline of 10 µg/m³ 5. That NO2 figure is a regional background over roughly 80 km: a busy street will be higher.
What should I do on a bad air day, or with smoke or dust?
- Bad air days: follow the ICA advice above and see Pollution episodes and Sensitive people and polluted air.
- Ozone: see Ozone days.
- Wildfire smoke: Phaenyx found no national smoke advice separate from the ICA. Watch official warnings (see our Spain alerts page) and read Wildfire smoke, A clean-air room at home and Masks for smoke.
- Dust: see Dust storms.
A household plan can list who in your home is sensitive to polluted air and where to shelter.
Frequently asked questions
Is Spain's index the same as the European one?
Not identical, but close. Its bands take into account criteria the European Environment Agency adopted for the European index, its health advice is in line with the European index, and it added the "extremadamente desfavorable" category after the European method was revised in November 2019 1.
Who counts as sensitive?
Adults and children with respiratory problems, and adults with heart conditions 1.
Why does the viewer sometimes show an asterisk?
Values estimated from the Copernicus (CAMS) model, used when a station has not reported, are followed by an asterisk 1.
Can I use the ICA to judge long-term pollution?
No. The index reflects short-term conditions and is not designed to check compliance with air quality rules 1.
Sources
- Boletín Oficial del Estado (BOE), Ministerio para la Transición Ecológica y el Reto Demográfico — Resolución de 2 de septiembre de 2020 por la que se modifica el Anexo de la Orden TEC/351/2019, por la que se aprueba el Índice Nacional de Calidad del Aire (BOE-A-2020-10426) — https://www.boe.es/buscar/doc.php?id=BOE-A-2020-10426 (accessed 2026-10-27)
- Ministerio para la Transición Ecológica y el Reto Demográfico (MITECO) — Índice Nacional de Calidad del Aire — https://ica.miteco.es/ (accessed 2026-10-27)
- Atmospheric Composition Analysis Group (ACAG), Washington University in St. Louis — Surface PM2.5, V6.GL.02.04 (annual mean 2021-2023) — https://sites.wustl.edu/acag/datasets/surface-pm2-5/ (accessed 2026-10-27)
- Copernicus Atmosphere Monitoring Service (CAMS) — CAMS global reanalysis (EAC4) — https://ads.atmosphere.copernicus.eu/ (accessed 2026-10-27)
- World Health Organization (WHO) — WHO global air quality guidelines (2021) — https://www.who.int/publications/i/item/9789240034228 (accessed 2026-10-27)
Turn this into action
Your plan for Spain, worked out for your household.
- Water, food and equipment counted for each person and pet
- The nuclear plants and zones around your home
- Phaenyx Safe: one tap to tell your people you are safe
Sources
- Boletín Oficial del Estado (BOE), Ministerio para la Transición Ecológica y el Reto Demográfico · Resolución de 2 de septiembre de 2020 por la que se modifica el Anexo de la Orden TEC/351/2019, por la que se aprueba el Índice Nacional de Calidad del Aire (BOE-A-2020-10426) checked 2026-10-27
- Ministerio para la Transición Ecológica y el Reto Demográfico (MITECO) · Índice Nacional de Calidad del Aire checked 2026-10-27
- Atmospheric Composition Analysis Group (ACAG), Washington University in St. Louis · Surface PM2.5, V6.GL.02.04 (annual mean 2021-2023) checked 2026-10-27
- Copernicus Atmosphere Monitoring Service (CAMS) · CAMS global reanalysis (EAC4) checked 2026-10-27
- World Health Organization (WHO) · WHO global air quality guidelines (2021) checked 2026-10-27