Air Quality in Great Britain for the Completed Day
- 1
Aberdeen →50 µg/m³ - 2Bristol →9 µg/m³
- 3City of London →6 µg/m³
- 4Dundee →2 µg/m³
Air quality in Great Britain
Cities of Great Britain for the last completed day (October 21, 2026, 00:00–24:00 UTC), as in the Data Hub. 51 sensors of the country are on the map.
Open methodology and data in JSON: Methodology and data sources · JSON · Data Hub
How the ranking is calculated
Charts and rankings use PM2.5 in µg/m³. The selected AQI standard, shown above each chart, only sets the colour scale; tables are sorted by measured PM2.5.
Data quality. Every night each sensor is checked for the previous day (UTC): coverage of readings, gaps, impossible values (PM2.5 outside 0–550 µg/m³), a frozen signal and a signal that barely changes over seven days. Sensors that fail are left out of the map, Data Hub, rankings and publications. Detailed readings are not kept before 20 September 2026; for those days a sensor counts if it passes the check today.
City values. Readings are averaged per sensor and hour; a sensor-day needs at least 12 valid hours. A city is shown only with at least four quality-checked sensors at different places: sensors closer than 500 m to each other count as one place. The daily value is the mean of its sensors for the last completed day (UTC). Cities with a PM2.5 value above 550 µg/m³ are left out.
Monthly tables. A sensor-month needs at least seven valid days, and a city month is the mean of its sensors. A city enters the yearly and 12-month tables with at least six months of data; months without data are gaps, not estimates. The worldwide table lists cities with an average AQI above 50 and at least three sensors reporting now. “Large cities” shows settlements classified as cities in OpenStreetMap; “All settlements” adds towns, villages and municipalities.
Updates. Statistics are recalculated once a day after the nightly quality check (around 04:00 UTC); live sensor counts refresh every few minutes. Values describe the available public sensors and are approximate: they are not official monitoring and do not assess a whole city.
Sources and licences. Visualisation © Atmy. Measurements keep their providers’ licences and attribution requirements; an aggregate cannot be relabelled as an Atmy licence.
- Sensor.Community: Database Contents License (DbCL) 1.0 with the applicable ODbL obligations.
- AirGradient: public API data, CC BY-SA 4.0; data redistributed through another service may have different terms.
- Nebo, AirVisual, PurpleAir, Atmy and government sources: terms must be verified with each provider. Test and unknown sources carry no verified licence.
Methodology and data sources · City ranking · API · Data terms