Air quality in Castres, Occitania, France today

Mr. Duck’s Air Quality Score

Moderate air today for Castres, Occitania, 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 Castres today is classified as Moderate. The primary pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 9.3 and a PM10 reference value of 11.0, based on four valid observations.

Data are shown via OpenAQ. 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 Castres air‑quality feed contains five measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter 10 µm or less (PM10) and particulate matter 2.5 µm or less (PM2.5). Data come from two monitoring stations, providing a total of ten individual rows of observations. For most pollutants the most recent reading was taken on 2026‑02‑10 at 15:00 UTC, while the NO data are older, last updated on 2024‑03‑11 at 09:00 UTC. This means that, apart from NO, the dataset reflects conditions within the past few days, whereas the NO record is more than a year out of date.

Across the five pollutants the observed concentrations span modest ranges. NO values range from 1.1 to 1.3 µg/m³ with a median of about 1.2 µg/m³; NO₂ varies between 8.3 and 19.6 µg/m³, centred around a median of roughly 14 µg/m³; O₃ is recorded from 26.5 up to 56.6 µg/m³ with a median near 42 µg/m³; PM10 shows values between 6.3 and 11.0 µg/m³, median about 8.7 µg/m³; and PM2.5 ranges from 5.4 to 9.3 µg/m³, median close to 7.4 µg/m³. The 10th‑percentile figures sit near the lower ends of each range, while the 90th‑percentile values approach the upper limits, indicating that most measurements fall within a relatively tight band but occasional higher readings do occur.

Because only two stations contribute data, spatial coverage across Castres is limited; conditions can differ in other neighbourhoods or at times not captured by these rows. The older NO timestamp further reduces confidence for that pollutant’s current state, while the other four pollutants benefit from very recent updates, giving a clearer snapshot of the city’s air quality on early February 2026.

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 data shown for Castres reflects four valid measurements and is updated within 3 days, with the latest values recorded at 2026‑02‑10T15:00:00+00:00. This snapshot provides a current view of city‑wide air quality but note that conditions can differ across neighbourhoods and change throughout the day, so local variations may not be captured in these figures.

OpenAQ station rows