Air quality in France: where to check and what to do

Short answer. Check the ATMO index, published every day for each commune by the approved regional air-quality associations (AASQA) and nationally at atmo-france.org/indiceatmo, with a forecast for today and tomorrow posted at 2 pm ¹. It has six levels, from "good" to "extremely poor" ¹. During a pollution episode, the prefect can issue health advice; sensitive people should prefer shorter, less strenuous outings ².

Where can I check air quality right now?

The AASQA are the approved regional associations that calculate and publish the index; Atmo France, cited here, is their national federation. Each AASQA publishes the ATMO index for its region on its own website, and you can find it nationally or near you at atmo-france.org/indiceatmo ¹. A forecast of the day's and the next day's index is published daily at 14:00 ¹. The index covers all of France, mainland and overseas; New Caledonia uses its own index ¹.

What do the index levels mean?

The six levels are bon (good), moyen (average), dégradé (degraded), mauvais (poor), très mauvais (very poor) and extrêmement mauvais (extremely poor) ¹. Since 2021 the ATMO index uses the same five pollutants, thresholds and labels as the European Air Quality Index: ozone, nitrogen dioxide, sulphur dioxide, PM10 and PM2.5 ¹. The worst of the five sets the day's level ¹.

Two limits matter. The index describes "background" air, away from specific sources such as busy roads, and it ignores unregulated pollutants such as ultrafine particles, pesticides and pollen ¹. It is also separate from pollution episodes: there is no direct link between the index and an episode being declared ¹. The behavioural advice attached to each index level is set by the health ministry and relayed by the AASQA ¹. See Air quality index explained.

How polluted is the air on average?

The population-weighted median of French cities shows about 9 µg/m³ of PM2.5 (annual mean 2021-2023) ³, almost twice the WHO guideline of 5 µg/m³ ⁵. Nitrogen dioxide is about 9.8 µg/m³ ⁴, at 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 during a pollution episode?

When an episode is forecast, the AASQA informs the prefecture, which decides whether to trigger the procedure ². There are two regulatory levels: an "information and recommendation" level aimed at sensitive and vulnerable people, and an "alert" level, where advice covers everyone and the prefect can impose measures such as speed limits ².

The official health messages, set by a ministerial order of 13 March 2018 ²:

Vulnerable people include pregnant women, infants and young children, people over 65, and people with heart or lung disease or asthma ². For the ATMO index alone, the advice when air is poor is to limit intense physical activity and avoid adding irritants such as tobacco smoke, indoor solvents and wood heating; in town, an anti-pollution mask does not reduce the health impact of air pollution ¹.

For smoke from fires or dust, see Wildfire smoke, A clean-air room at home, Masks for smoke and Dust storms. Also read Pollution episodes, Ozone days and Children and polluted air. A household plan can note who at home is sensitive to polluted air.

Frequently asked questions

Is the French ATMO index the same as the European index?

Since 2021 it uses the same five pollutants, the same thresholds and the same labels ¹.

Who declares a pollution episode in France?

The prefecture, after the regional AASQA forecasts the episode ².

Should my child still play sport on a poor air day?

On a poor ATMO day, the advice is to keep your child's sport but lower its intensity ¹. During an official episode, follow the prefect's advice ².

Does the index show pollution in my street?

No. It describes background air away from sources such as busy roads ¹.