Spain has emerged as one of Europe’s clean‑city leaders when it comes to the number of places that meet the WHO’s guidelines for clean air. While the country as a whole still sits above that strict benchmark, it now compares favourably with some of its biggest European neighbours and several major capitals.
Spain’s Air Quality Compared with Other European Countries
According to the IQAir World Air Quality Report 2025, Spain recorded a population‑weighted annual average PM2.5 concentration of 9.1 µg/m³. This places the country 13th out of 43 European countries when ordered from cleanest to most polluted, ahead of Germany, France, and Italy.
Only three European countries reported national annual PM2.5 averages below the WHO guideline of 5 µg/m³: Iceland, Estonia, and Andorra.
At the other end of the scale, Bosnia and Herzegovina recorded the highest value in Europe, with a PM2.5 concentration of 23.4 µg/m³.
Spain’s “Clean City” Leadership in Europe
Where Spain really stands out in the IQAir World Air Quality Report 2025 is in the number of cities that already meet the WHO annual PM2.5 guideline.
Across Europe, 2,302 cities were monitored in 2025, and only 104 recorded annual PM2.5 levels below 5 µg/m³. Among them:
- Finland came out on top with 25 cities
- Sweden followed with 15
- Spain ranked third with 12
For a large, densely populated country, Spain’s 12 cities below the WHO guideline place it in a small group with an unusually high number of very clean urban environments.
Spain’s Air Quality in the Global Ranking
Globally, Spain sits in the cleaner half of the countries and territories assessed, though it remains above the WHO guideline.
On the IQAir list of 143 countries, regions, and territories, Spain is ranked as the 39th cleanest country. To place this in context, it helps to look at the global extremes:
|
French Polynesia |
1.8 |
Cleanest in the ranking |
|
Spain |
9.1 |
Cleaner half |
|
Pakistan |
67.3 |
Most polluted |
Madrid’s Air Quality Compared with Other Capitals
For many foreigners, Madrid’s air quality is the most relevant indicator when assessing life in Spain. The IQAir 2025 ranking orders 124 capital cities from cleanest to most polluted by average PM2.5.
Madrid records an annual average of 8.5 µg/m³, making it the 30th cleanest of the 124 capital cities. Madrid’s air quality is slightly worse than Copenhagen’s, with the Danish capital recording a lower annual PM2.5 concentration. However, it is better than the annual averages recorded in Rome, Berlin, Amsterdam, London, and Paris.
At the extremes of the capital‑city ranking, New Delhi recorded the worst air quality, with an annual average of 82.2 µg/m³, while Papeete in French Polynesia was the cleanest, at 1.5 µg/m³.
Understanding PM2.5 in the IQAir World Air Quality Report
PM2.5 refers to fine particulate matter with a diameter of 2.5 micrometres or smaller. These particles are small enough to travel deep into the lungs and can enter the bloodstream, which is why they are closely linked to heart and lung conditions.
The current WHO annual guideline for PM2.5 is 5 µg/m³. Levels at or below this threshold are associated with significantly reduced long‑term health risks, though not the complete absence of risk.
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