Air quality in Rennes, Brittany, France today

Mr. Duck’s Air Quality Score

Good air today for Rennes, Brittany, France

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality in Rennes today is classified as Good. The main pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 1.5 and a PM10 reference value of 4.0, based on eight valid observations collected via OpenAQ.

Overall conditions meet the criteria for a Good rating according to the latest assessment. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The Rennes air‑quality dataset currently contains eight measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO2), ozone (O3), particulate matter of 1 µm (PM1), 2.5 µm (PM2.5) and 10 µm (PM10), relative humidity and temperature – drawn from a total of thirty‑one rows supplied by OpenAQ. The number of distinct monitoring stations varies by pollutant: NO2, PM2.5, PM10 and O3 each have data from six to eight recent rows, while NO is represented by five rows that are older (the most recent reading dates back to 2024‑03‑11). For PM1, relative humidity and temperature only a single row is present and its timestamp is unknown, so these three variables lack fresh updates.

Across the pollutants with recent data (updated within the last three days), the newest timestamps cluster on 2026‑02‑10 at 15:00 UTC. NO2 shows values ranging from 6.25 to 39.35 µg/m³ with a median of about 18 µg/m³; PM2.5 spans 0.0 to 23.93 µg/m³, median roughly 3.5 µg/m³; PM10 varies between 2.7 and 28.9 µg/m³, median near 21.8 µg/m³; O3 is recorded from 33.4 up to 84.75 µg/m³, median around 40.7 µg/m³. The spread for each of these pollutants is noticeable – the 10th‑percentile values are close to the minima while the 90th‑percentile values approach the maxima, indicating that measurements capture both low and high concentrations within the city.

Overall, most of the dataset is recent, but a substantial share (17 rows) is classified as old and six rows have unknown freshness. The uneven coverage—especially the lack of up‑to‑date PM1, humidity and temperature readings—means that while the core pollutants give a fairly current picture of Rennes’ air quality, conditions can still differ across neighborhoods and times not captured by the available stations.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The current dataset for Rennes includes eight valid measurements and is updated within three days, with the latest refresh recorded at 2026‑02‑10 15:00 UTC. These figures represent a snapshot of ambient conditions captured by the monitoring network; however, air quality can vary across different neighbourhoods and times of day within the city, so local values may differ from those shown here.

OpenAQ station rows