European City Air Quality Rankings: Nordic Capitals Dominate List in the Latest Update
In an effort to provide more accurate and timely information about air quality in European cities, the European Air Quality Index (EAQI) has undergone a significant update. This new methodology, introduced in 2025, calculates air pollution levels by considering hourly measurements of five key pollutants: particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), ozone (O3), and sulphur dioxide (SO2).
The EAQI, launched in 2017, is an online tool operated by the European agency that offers users insights into local air pollution and its impact on health. The updated service uses hourly data for all key pollutants to estimate the index, offering a near real-time and multi-pollutant perspective.
Previously, the city air quality rankings focused on long-term exposure risks rather than hourly values. Cities were ranked based on the annual average concentrations of fine particulate matter (PM2.5) alone, derived from limited monitoring stations. This older approach included fewer cities and excluded other key pollutants, limiting the comprehensiveness of comparisons.
The 2025 update, however, expands the scope by using hourly data for five key pollutants, offering a near real-time and multi-pollutant perspective. It also applies a ranking based on the risk of mortality linked to long-term exposure to PM2.5, NO2, and O3 over the past two years, thus incorporating health impact assessments in the city air quality viewer. This shift has increased the number of cities analysed to over 760, including those with populations above 50,000, for a broader and more representative assessment across Europe.
The updated European city air quality viewer, which can be downloaded for Android and iOS users, now includes data on fine particulate matter, nitrogen dioxide, and ozone, providing a more comprehensive comparison of air quality in cities. It ranks cities from the cleanest city to the most polluted, based on the risk of mortality associated with long-term exposure to these pollutants over the past two calendar years.
Notably, Stockholm, Reykjavik, and Helsinki rank as the cleanest European capital cities in terms of air quality, according to the updated European city air quality viewer.
Forecast air quality levels are provided by the Copernicus Atmospheric Monitoring Service for the European Air Quality Index, ensuring users have access to the most up-to-date information. The European city air quality viewer and the European Air Quality Index focus on long-term air quality, as long-term exposure to air pollution causes the most serious health effects.
This update improves accuracy, frequency, and pollutant coverage for air quality measurement in European cities, moving beyond just PM2.5 annual averages to a more dynamic and health-risk-focused methodology that enables better-informed public awareness and policy decisions.
- The update of the European Air Quality Index (EAQI) in 2025, which uses hourly data for five key pollutants, aims to provide a more accurate and timely assessment of air quality and its impact on health, as it estimates the index using scientific environmental-science methodologies.
- The new EAQI methodology, introduced in 2025, not only considers long-term exposure risks but also focuses on the health-and-wellness impacts of air pollution, as it ranks cities based on the mortality risk linked to long-term exposure to PM2.5, NO2, and O3 over the past two years.
- By expanding its scope to include hourly data for five key pollutants and applying a ranking based on health impact assessments, the updated EAQI increases its coverage to over 760 cities across Europe, promoting sustainability and combating climate-change issues by offering a near real-time and multi-pollutant perspective on city air quality.
