Worst air pollution Rennes, today and tomorrow

Today (16 July): Air quality in Rennes is fair. NO2 is fair; AQI and O3 are medium; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 6:00 PM (O3: 45.0/100).
Tomorrow (17 July 2026): Air quality in Rennes is fair. All pollutants stay as today. Pollution peaks around 3:00 PM (O3: 43.0/100). Airmine updates local air quality forecasts four times daily.

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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

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Rennes' air quality benefits from consistent Breton Atlantic westerlies providing reliable maritime ventilation across this northwestern French city, with generally good readings for a major French metropolitan area. Vehicle traffic on the ring road is the primary local source, while the surrounding Ille-et-Vilaine agricultural landscape contributes ammonia from intensive pig and poultry farming that is one of Brittany's distinctive secondary particulate formation sources alongside the primary vehicle NOₓ throughout the year.

Today - 16 July | Pollution peaks at 18:00

AQI:

Medium

45.0/100

PM2.5 (fine particles):

Good

14.5/100

PM10 (coarse particles):

Good

4.9/100

NO2 (nitrogen dioxide):

Fair

32.5/100

O3 (ozone):

Medium

45.0/100

SO2 (sulfur dioxide):

Good

1.4/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

8.8/100

PM1 (ultrafine particles):

Good

18.0/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 15:00

AQI:

Medium

43.0/100

PM2.5 (fine particles):

Good

10.2/100

PM10 (coarse particles):

Good

3.2/100

NO2 (nitrogen dioxide):

Fair

21.5/100

O3 (ozone):

Medium

43.0/100

SO2 (sulfur dioxide):

Good

1.4/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

5.0/100

PM1 (ultrafine particles):

Good

12.9/100

Pollen forecast in Rennes

View pollen forecast

Frequently Asked Questions

Is air quality bad in Rennes right now?

On 16 July 2026, overall air quality in Rennes is fair. NO2 is the main pollutant at 32.5/100. Pollution peaks around 6:00 PM (O3: 45.0/100).

Will air quality be worse tomorrow in Rennes?

On 17 July 2026, air quality conditions in Rennes will be similar to today, with NO2 forecast at fair at 21.5/100. Pollution peaks around 3:00 PM (O3: 43.0/100).

When is air pollution at its worst in Rennes?

The days that hit sensitive groups hardest in Rennes are calm spring ones, when fishing-port and coastal traffic and the birch and oak pollen peak overlap; Atlantic sea breezes ventilate the coast reliably, so relief usually isn't far behind. Nearby Breton dairy pasture and coastal farmland add a further seasonal factor.

Are air quality levels in Rennes based on measurements or forecasts?

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

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Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)

This forecast is produced independently using Airmine's own atmospheric data and models.

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.

For long term forecasts and maps, see the Airmine app