Air quality in Liège, Liège, Belgium today

Mr. Duck’s Air Quality Score

Good air today for Liège, Liège, Belgium

⚠️ 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 Liège is currently classified as Good. The main pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 3.0 and a PM10 reference value of 4.0, based on eleven valid observations collected via OpenAQ.

Overall conditions meet the criteria for the Good category 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 Liège air‑quality dataset contains observations for nine measured variables: carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), particulate matter of 1 µm (PM1), 2.5 µm (PM2.5) and 10 µm (PM10), relative humidity, sulphur dioxide (SO2) and temperature (the latter is not reported in the current rows). The data come from a total of five monitoring stations, but the number of rows varies by pollutant because some sensors have only one recent record while others provide several. For example, PM10 and PM2.5 each have five recent rows with the latest update on 2026‑02‑10 at 18:00 UTC, whereas SO2 has two rows whose most recent entry is older, from 2026‑01‑14 at 08:00 UTC. CO, NO2 and O3 also show two rows each, all refreshed within the last three days (the newest timestamp being 2026‑02‑10 18:00 UTC for CO and NO2, and 2026‑02‑10 17:00 UTC for O3). PM1 and relative humidity are represented by a single row dated 2025‑10‑12 14:00 UTC, which the system flags as “old data”.

Across the pollutants that have multiple recent entries, the observed ranges are modest for fine particles: PM10 values span from 0.0 to 56.1 µg/m³ with a median of 3.5 µg/m³, and PM2.5 range from 0.0 to 31.5 µg/m³ with a median of 2.5 µg/m³. Gaseous pollutants show broader spreads: CO varies between 245 and 1500 µg/m³ (median 872.5), NO2 between 10 and 34.5 µg/m³ (median 22.3) and SO2 between 0.5 and 1.0 µg/m³ (median 0.75). Ozone is currently reported as a single constant value of 60 µg/m³ from the latest reading.

Overall, most pollutants have at least one measurement updated within the past three days, but coverage is uneven—PM1 and humidity rely on older data, and temperature is absent from the present rows. Consequently, while recent snapshots give a picture of current conditions in parts of Liège, the city’s air quality can still differ across neighborhoods and times not captured by these limited and sometimes dated records.

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 Liège reflects 11 valid measurements and is Updated within 3 days, with the latest values recorded at 2026‑02‑10T18:00:00+00:00. This snapshot provides a current overview of city‑wide air quality, but conditions can differ across neighborhoods and change throughout the day, so local variations may not be captured in these figures.

OpenAQ station rows