Air Quality

Data values	Data description	Year	Pollutant	Area
7	µg/m3	2023	NO2	Wales
3	µg/m3	2023	NO2	Isle of Anglesey
3	µg/m3	2023	NO2	Gwynedd
4	µg/m3	2023	NO2	Conwy
4	µg/m3	2023	NO2	Denbighshire
6	µg/m3	2023	NO2	Flintshire
6	µg/m3	2023	NO2	Wrexham
2	µg/m3	2023	NO2	Ceredigion
4	µg/m3	2023	NO2	Pembrokeshire
4	µg/m3	2023	NO2	Carmarthenshire
7	µg/m3	2023	NO2	Swansea
7	µg/m3	2023	NO2	Neath Port Talbot
7	µg/m3	2023	NO2	Bridgend
7	µg/m3	2023	NO2	Vale of Glamorgan
13	µg/m3	2023	NO2	Cardiff
7	µg/m3	2023	NO2	Rhondda Cynon Taf
8	µg/m3	2023	NO2	Caerphilly
6	µg/m3	2023	NO2	Blaenau Gwent
7	µg/m3	2023	NO2	Torfaen
6	µg/m3	2023	NO2	Monmouthshire
11	µg/m3	2023	NO2	Newport
3	µg/m3	2023	NO2	Powys
6	µg/m3	2023	NO2	Merthyr Tydfil
5	µg/m3	2023	NO2	Betsi Cadwaladr University Health Board
3	µg/m3	2023	NO2	Powys Teaching Health Board
4	µg/m3	2023	NO2	Hywel Dda University Health Board
8	µg/m3	2023	NO2	Aneurin Bevan University Health Board
11	µg/m3	2023	NO2	Cardiff and Vale University Health Board
7	µg/m3	2023	NO2	Cwm Taf Morgannwg University Health Board
7	µg/m3	2023	NO2	Swansea Bay University Health Board
9	µg/m3	2023	PM10	Wales
7	µg/m3	2023	PM10	Isle of Anglesey
7	µg/m3	2023	PM10	Gwynedd
8	µg/m3	2023	PM10	Conwy
8	µg/m3	2023	PM10	Denbighshire
9	µg/m3	2023	PM10	Flintshire
9	µg/m3	2023	PM10	Wrexham
8	µg/m3	2023	PM10	Ceredigion
8	µg/m3	2023	PM10	Pembrokeshire
8	µg/m3	2023	PM10	Carmarthenshire
9	µg/m3	2023	PM10	Swansea
9	µg/m3	2023	PM10	Neath Port Talbot
9	µg/m3	2023	PM10	Bridgend
9	µg/m3	2023	PM10	Vale of Glamorgan
11	µg/m3	2023	PM10	Cardiff
9	µg/m3	2023	PM10	Rhondda Cynon Taf
9	µg/m3	2023	PM10	Caerphilly
8	µg/m3	2023	PM10	Blaenau Gwent
9	µg/m3	2023	PM10	Torfaen
9	µg/m3	2023	PM10	Monmouthshire
10	µg/m3	2023	PM10	Newport
8	µg/m3	2023	PM10	Powys
9	µg/m3	2023	PM10	Merthyr Tydfil
8	µg/m3	2023	PM10	Betsi Cadwaladr University Health Board
8	µg/m3	2023	PM10	Powys Teaching Health Board
8	µg/m3	2023	PM10	Hywel Dda University Health Board
9	µg/m3	2023	PM10	Aneurin Bevan University Health Board
10	µg/m3	2023	PM10	Cardiff and Vale University Health Board
9	µg/m3	2023	PM10	Cwm Taf Morgannwg University Health Board
9	µg/m3	2023	PM10	Swansea Bay University Health Board
5	µg/m3	2023	PM2.5	Wales
4	µg/m3	2023	PM2.5	Isle of Anglesey
4	µg/m3	2023	PM2.5	Gwynedd
4	µg/m3	2023	PM2.5	Conwy
5	µg/m3	2023	PM2.5	Denbighshire
5	µg/m3	2023	PM2.5	Flintshire
5	µg/m3	2023	PM2.5	Wrexham
4	µg/m3	2023	PM2.5	Ceredigion
5	µg/m3	2023	PM2.5	Pembrokeshire
5	µg/m3	2023	PM2.5	Carmarthenshire
5	µg/m3	2023	PM2.5	Swansea
5	µg/m3	2023	PM2.5	Neath Port Talbot
5	µg/m3	2023	PM2.5	Bridgend
5	µg/m3	2023	PM2.5	Vale of Glamorgan
7	µg/m3	2023	PM2.5	Cardiff
6	µg/m3	2023	PM2.5	Rhondda Cynon Taf
6	µg/m3	2023	PM2.5	Caerphilly
5	µg/m3	2023	PM2.5	Blaenau Gwent
6	µg/m3	2023	PM2.5	Torfaen
5	µg/m3	2023	PM2.5	Monmouthshire
6	µg/m3	2023	PM2.5	Newport
5	µg/m3	2023	PM2.5	Powys
5	µg/m3	2023	PM2.5	Merthyr Tydfil
5	µg/m3	2023	PM2.5	Betsi Cadwaladr University Health Board
5	µg/m3	2023	PM2.5	Powys Teaching Health Board
5	µg/m3	2023	PM2.5	Hywel Dda University Health Board
6	µg/m3	2023	PM2.5	Aneurin Bevan University Health Board
6	µg/m3	2023	PM2.5	Cardiff and Vale University Health Board
5	µg/m3	2023	PM2.5	Cwm Taf Morgannwg University Health Board
5	µg/m3	2023	PM2.5	Swansea Bay University Health Board
8	µg/m3	2022	NO2	Wales
3	µg/m3	2022	NO2	Isle of Anglesey
3	µg/m3	2022	NO2	Gwynedd
4	µg/m3	2022	NO2	Conwy
5	µg/m3	2022	NO2	Denbighshire
8	µg/m3	2022	NO2	Flintshire
8	µg/m3	2022	NO2	Wrexham
3	µg/m3	2022	NO2	Ceredigion
4	µg/m3	2022	NO2	Pembrokeshire
5	µg/m3	2022	NO2	Carmarthenshire

Showing 1 to 100 of 1,530 rows

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Main information

• Most recent update: 31 October 2025
• Next update expected: August 2026
• Designation: No designation
• Data provider 1: Department for Environment, Food and Rural Affairs
• Data source 1: Air concentration
• Data provider 2: Office for National Statistics (ONS)
• Data source 2: Small Area Population Estimates (SAPE)
• Data provider 3: Welsh Government
• Data source 3: Geographical information

Data notes

• Rounding applied:

  whole number

Overview

• Summary of dataset and variables:

  Air Quality Exposure Indicators - average, population weighted NO2, PM2.5 and PM10 concentrations across local authority areas and health board areas, derived from modelled data for each square kilometre in Wales, measured in µg/m3 (DEFRA data)

  µg/m3 = microgrammes per cubic metre NO2 = Nitrogen Dioxide PM10 = fine particulate matter with a diameter of 10 micrometers or less PM2.5 = fine particulate matter with a diameter of 2.5 micrometers or less

• Data collection or calculation:

  Each year the UK Government’s Pollution Climate Mapping (PCM) model calculates average pollutant concentrations for each square kilometre of the UK. The model is calibrated against measurements taken from the UK’s national air quality monitoring network.

  This data is combined with mid-year population data and dwelling data to provide population weighted data.

  For each census output area (statistical geographic units comprising around 150 properties), the pollutant concentrations are weighted by the number of dwellings in each square kilometre to give an average NO2, PM2.5 and PM10 concentration across the census output area.

  For each Local Authority and Local Health Board, a population-weighted average over its constituent census output areas were calculated to give an average NO2, PM2.5 and PM10 concentration based on where people live in those Local Authorities and Health Boards. The same calculation was also repeated over all census output areas, to give a comparable figure for the whole of Wales.

• Statistical quality:

  Each year the Pollution Climate Model (PCM) which underpin the background maps is refined and improved ( to account for latest available science and understanding e.g. changes in emissions factors, improved activity data etc.). These method changes are usually only applied in the latest year's figures. See Defra Air Quality report.

  2021 air quality figures are based on 2020 population estimates. 2023 air quality figures are based on 2022 population estimates.

• Related reports:
  • Modelled background pollution data
  • UK-Air GIS mapping

Published by

• Organisation: Welsh Government
• Contact email: stats.environment@gov.wales

Metadata

The metadata for this dataset is not included when you download the data. You can download this separately. This contains all the information from the 'About this dataset' tab.