Air quality in Montlhéry, Ile-de-France, France today
Mr. Duck’s Air Quality Score
Moderate air today for Montlhéry, Ile-de-France, France
This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.
Air quality today
The air quality in Montlhéry today is classified as Moderate. The primary pollutant identified is PM2.5 (fine particles).
Measurements from OpenAQ show a PM2.5 reference value of 16.4 µg/m³ based on two valid observations. No PM10 reference value is available for this 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 Montlhéry air‑quality record draws on a single monitoring station that reports three pollutants: nitrogen monoxide (NO), nitrogen dioxide (NO₂) and fine particulate matter (PM2.5). Because there is just one row of data, the coverage is limited to the RN20 – MONTLHERY site, so conditions elsewhere in the city are not captured.
The most recent NO measurement dates back to 2024‑03‑11 09:00 UTC and shows a value of 95.4 µg/m³; this entry is flagged as “old data.” In contrast, the NO₂ reading is much fresher, recorded on 2026‑02‑10 15:00 UTC with a single value of 48.0 µg/m³ and classified as updated within three days. The PM2.5 figure comes from 2026‑02‑09 03:00 UTC, also marked as updated within seven days, and registers 16.4 µg/m³.
All three pollutants have identical minimum, median and maximum values, indicating that each has only one observation in the dataset. Consequently, there is no spread or variability to describe for any of them. The freshness of the data varies: NO is over two years old, while NO₂ and PM2.5 are less than a week old at the time of writing. This uneven timeliness means that recent conditions for nitrogen monoxide are not reflected, whereas the other two pollutants provide a current snapshot.
Overall, the dataset offers a very narrow view—one location, one reading per pollutant—with mixed recency. Users should keep in mind that air quality can differ across neighborhoods and times, and the available figures represent only the specific moments captured at the RN20 – MONTLHERY monitoring point.
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 dataset for Montlhéry contains two valid measurements and is refreshed regularly, having been updated within the past three days (last update: 2026‑02‑10 15:00 UTC). While these figures give a current snapshot of air quality, conditions can differ across neighborhoods and change throughout the day, so local variations may not be fully captured in this summary.
OpenAQ station rows
| Station | Parameter | Value | Unit | Last updated |
|---|---|---|---|---|
| RN20 - MONTLHERY | no | 95.4 | µg/m³ | 2024-03-11 09:00 UTC |
| RN20 - MONTLHERY | no2 | 48.0 | µg/m³ | 2026-02-10 15:00 UTC |
| RN20 - MONTLHERY | pm25 | 16.4 | µg/m³ | 2026-02-09 03:00 UTC |