Trends - Air Quality Indicators

These pages present a series of graphs showing how air quality in Wales has changed in recent years. The statistics shown in these graphs are based upon measurements made at automatic monitoring sites in Wales. Part of the Government's plans to ensure a better quality of life for all in the UK include a series of Indicators of Sustainable Development. These include a range of indicators based on air quality:

  • Annual mean concentration of nitrogen dioxide
  • Annual mean concentrations of the pollutants particulate matter (measured as PM10), and ozone.

Further information on the air quality indicators can be found on the following Defra web page:The Headline Air Quality Indicator.  We present a series of graphs which have been calculated based on the latest figures up to 2022/23 for Air Quality in Wales.