Air quality in Cardiff, Wales, United Kingdom today

Mr. Duck’s Air Quality Score

Good air today for Cardiff, Wales, United Kingdom

⚠️ 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 Cardiff today is classified as Good. The primary pollutant identified is PM2.5 (fine particles).

Measurements recorded for the day show a PM2.5 reference value of 6.0 and a PM10 reference value of 6.0, based on eight valid observations collected 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 Cardiff air‑quality data set contains measurements for six common pollutants – carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter 10 µm or smaller (PM₁₀), particulate matter 2.5 µm or smaller (PM₂.₅) and sulphur dioxide (SO₂). These values come from eight individual rows of sensor readings, but they are all reported by just two monitoring stations in the city centre (identified as UKA00217).

All of the pollutants have recent updates within the past week. The most recent timestamp for CO, O₃, PM₂.5 and SO₂ is 2026‑02‑10 19:00 UTC, while NO₂, PM₁₀ and the other four are recorded at 2026‑02‑10 20:00 UTC, showing that the data are refreshed daily. The CO reading is a single value of 151.346 µg/m³, and O₃, PM₂.5 and SO₂ each have one constant measurement (47.0 µg/m³, 6.0 µg/m³ and 1.0 µg/m³ respectively). In contrast, NO₂ and PM₁₀ are based on two rows each, providing a modest spread: NO₂ ranges from 23.0 to 66.36 µg/m³ with a median of about 44.68 µg/m³, while PM₁₀ varies between 6.0 and 9.66 µg/m³ with a median near 7.83 µg/m³.

Because the dataset relies on only two stations, it captures conditions at a limited number of locations within Cardiff. The presence of multiple rows for NO₂ and PM₁₀ gives a small glimpse of variability, whereas the single‑row pollutants show no observed range in this snapshot. Consequently, while the timestamps are fresh, the spatial coverage is narrow, meaning actual city‑wide air quality can differ across neighborhoods and times not represented here.

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 Cardiff includes eight valid measurements and is marked as Updated within 3 days, with the most recent data recorded on 2026‑02‑10 at 20:00 UTC. These figures represent a snapshot of conditions across the monitoring network at that time. Air quality can vary by location and time within the city, so individual experiences may differ from the values shown here.

OpenAQ station rows