Click a row to add that site to the charts on the Explore tab. Sites need 9 of the last 12 months to get a mean.
Values are monthly means in µg/m³. The data-capture filter in More options applies here too.
Download CSVAbout this app
Monthly mean concentrations from Defra's Automatic Urban and Rural Network (AURN), downloaded with the openair R package from UK-AIR .
How the data stays up to date
The app keeps a saved copy of the data. When someone opens it and that copy is more than 24 hours old, it re-downloads the current and previous year from Defra (the only years that change) and merges them in. You can also press Check for new data .
Recent months are provisional and may be revised when Defra ratifies the data.
Benchmarks (annual mean, µg/m³)
How the numbers are worked out
- 12-month mean: the average of the last 12 monthly means, ending at the latest month available anywhere in the network. Sites need at least 9 months to get a value.
- This is a quick indicator, not a formal compliance assessment, which uses ratified hourly data.
- Seasonal pattern: the average for each calendar month across the chosen dates; the shaded band is ±1 standard deviation.