Defra publishes 2025 UK air quality compliance data tables
Defra has published the data tables that underpin its Air Pollution in the UK 2025 report, which sets out the results of the UK's annual compliance assessment under the Air Quality Standards Regulations (2010).
The assessment compares measured and modelled concentrations of air pollutants against the limits and targets set in the regulations. For 2025, Defra says the assessment uses a new, more advanced national model.
Tables replaced after corrections
Defra has replaced several of the published tables:
- Nitrogen dioxide (NO2): the tables now include the UK Urban NO2 Network (UUNN) Red Flag assessment. Two sampling points that received a red flag have been removed.
- Ozone (O3): multi-year averages from measurements have been corrected. The requirements for the three-year count of days above the target value and the one-year AOT40 long-term objective have also been corrected.
- Lead: the tables have been replaced so that the correct unit of measurement is used for the reported data.
The data is published on GOV.UK. Manufacturers and suppliers who need to check local or national pollutant levels, for example when preparing permit applications or environmental reporting, should make sure they are working from the replaced versions of the tables.