What's the air quality in Gwynedd? NO₂ 2.3 µg/m³
In 2025 the average resident of Gwynedd lived with background NO₂ of 2.3 µg/m³, Very Low for England and Wales and below the WHO guideline of 10. PM2.5 was 4.5 µg/m³, Very Low for England and Wales and below the WHO guideline of 5. The typical area in England and Wales has NO₂ of 7.2 and PM2.5 of 7.4 µg/m³.
- PM2.5
- 4.5 µg/m³
- NO₂ for England and Wales
- Very Low
- Figures for
- 2025 annual average
Modelled background levels averaged over where residents live (Census 2021), not roadside levels. Contains public sector information licensed under the Open Government Licence v3.0. Source: Defra modelled background pollution, 2025. How we calculate this
All house prices in GwyneddIs the air quality good in Gwynedd?
Background NO₂ in Gwynedd is 2.3 µg/m³, below the WHO guideline of 10, and lower than the typical area (7.2). That puts it in the Very Low band. Background PM2.5 in Gwynedd is 4.5 µg/m³, below the WHO guideline of 5, and lower than the typical area (7.4). That puts it in the Very Low band. Most of England and Wales is above the WHO guideline for PM2.5, so the bands compare places with each other rather than giving a pass or fail.
Nitrogen dioxide (NO₂): 2.3 µg/m³
NO₂ level is Very Low, on a scale from Very Low to Very High.
Very Low means the lowest fifth of areas in England and Wales for NO₂.
| Very Low | up to 4.7 |
|---|---|
| Low | 4.7 to 6.5 |
| Typical | 6.5 to 7.7 |
| High | 7.7 to 9.2 |
| Very High | over 9.2 |
WHO guideline: 10 µg/m³ (in the Very High band). UK legal limit: 40 µg/m³.
Fine particles (PM2.5): 4.5 µg/m³
PM2.5 level is Very Low, on a scale from Very Low to Very High.
Very Low means the lowest fifth of areas in England and Wales for PM2.5.
| Very Low | up to 6.0 |
|---|---|
| Low | 6.0 to 7.2 |
| Typical | 7.2 to 7.7 |
| High | 7.7 to 8.2 |
| Very High | over 8.2 |
WHO guideline: 5 µg/m³ (in the Very Low band). UK legal limit: 20 µg/m³, with a target of 10 µg/m³ in England by 2040.
The bands split every area we cover into fifths by its level, from Very Low to Very High. The map uses the same colours.
Which part of Gwynedd has the cleanest air?
Aberdaron has the lowest background NO₂ of the 64 areas of Gwynedd, at 1.2 µg/m³. Bangor has the highest, at 4.6 µg/m³. Average house prices are shown alongside, so you can weigh air quality against cost.
| Area | NO₂ | PM2.5 | NO₂ band | Average price |
|---|---|---|---|---|
| AberdaronVery Low | 1.2 | 4.7 | Very Low | £363,571 |
| Llanfihangel-y-PennantVery Low | 1.2 | 4.1 | Very Low | £241,500 |
| ArthogVery Low | 1.2 | 4.2 | Very Low | £149,380 |
| GanllwydVery Low | 1.3 | 4.0 | Very Low | £310,000 |
| LlangelyninVery Low | 1.3 | 4.4 | Very Low | £408,016 |
| PistyllVery Low | 1.3 | 4.3 | Very Low | £182,833 |
| LlanenganVery Low | 1.3 | 4.5 | Very Low | £385,534 |
| BotwnnogVery Low | 1.3 | 4.6 | Very Low | £262,000 |
| Brithdir and LlanfachrethVery Low | 1.3 | 4.0 | Very Low | £238,999 |
| TudweiliogVery Low | 1.3 | 4.6 | Very Low | £348,600 |
| Betws GarmonVery Low | 1.3 | 3.8 | Very Low | £303,750 |
| TrawsfynyddVery Low | 1.3 | 4.0 | Very Low | £165,499 |
| BarmouthVery Low | 1.4 | 4.3 | Very Low | £212,678 |
| HarlechVery Low | 1.4 | 4.3 | Very Low | £192,858 |
| TalsarnauVery Low | 1.4 | 4.1 | Very Low | £217,785 |
| Dyffryn ArdudwyVery Low | 1.4 | 4.3 | Very Low | £243,350 |
| BeddgelertVery Low | 1.4 | 4.0 | Very Low | £247,014 |
| LlanaelhaearnVery Low | 1.4 | 4.3 | Very Low | £159,625 |
| LlanegrynVery Low | 1.4 | 4.5 | Very Low | £171,000 |
| LlanbedrVery Low | 1.4 | 4.3 | Very Low | £251,904 |
| BuanVery Low | 1.4 | 4.5 | Very Low | £179,500 |
| NefynVery Low | 1.4 | 4.5 | Very Low | £245,555 |
| Bryn-CrugVery Low | 1.5 | 4.5 | Very Low | £347,500 |
| CorrisVery Low | 1.5 | 4.2 | Very Low | £206,600 |
| LlanelltydVery Low | 1.5 | 4.1 | Very Low | £300,000 |
| LlanfairVery Low | 1.5 | 4.4 | Very Low | £387,317 |
| LlanbedrogVery Low | 1.5 | 4.6 | Very Low | £287,803 |
| LlanfrothenVery Low | 1.5 | 4.2 | Very Low | £290,000 |
| DolgellauVery Low | 1.5 | 4.1 | Very Low | £175,344 |
| MaentwrogVery Low | 1.5 | 4.2 | Very Low | £199,416 |
| LlanycilVery Low | 1.6 | 4.2 | Very Low | £216,000 |
| LlanberisVery Low | 1.6 | 3.8 | Very Low | £282,824 |
| LlanuwchllynVery Low | 1.6 | 4.1 | Very Low | £196,000 |
| LlanllyfniVery Low | 1.6 | 4.1 | Very Low | £148,267 |
| DolbenmaenVery Low | 1.6 | 4.3 | Very Low | £171,166 |
| LlanystumdwyVery Low | 1.6 | 4.6 | Very Low | £242,447 |
| LlangywerVery Low | 1.6 | 4.1 | Very Low | £222,000 |
| ClynnogVery Low | 1.7 | 4.2 | Very Low | £274,000 |
| LlannorVery Low | 1.7 | 4.5 | Very Low | £247,850 |
| WaunfawrVery Low | 1.7 | 4.0 | Very Low | £233,115 |
| PennalVery Low | 1.7 | 4.5 | Very Low | £444,166 |
| FfestiniogVery Low | 1.7 | 4.1 | Very Low | £136,383 |
| MawddwyVery Low | 1.7 | 4.3 | Very Low | £256,050 |
| LlanwndaVery Low | 1.7 | 4.1 | Very Low | £266,300 |
| AberdoveyVery Low | 1.7 | 4.8 | Very Low | £311,363 |
| LlandwrogVery Low | 1.7 | 4.2 | Very Low | £278,108 |
| CricciethVery Low | 1.8 | 4.9 | Very Low | £299,640 |
| TywynVery Low | 1.8 | 4.7 | Very Low | £229,690 |
| PwllheliVery Low | 1.8 | 4.7 | Very Low | £223,266 |
| LlanddeiniolenVery Low | 1.8 | 4.1 | Very Low | £226,884 |
| BethesdaVery Low | 1.9 | 3.8 | Very Low | £175,202 |
| LlandderfelVery Low | 1.9 | 4.3 | Very Low | £150,166 |
| LlanrugVery Low | 2.0 | 4.1 | Very Low | £218,625 |
| PenrhyndeudraethVery Low | 2.1 | 4.6 | Very Low | £173,903 |
| BalaVery Low | 2.1 | 4.4 | Very Low | £165,100 |
| LlandygaiVery Low | 2.2 | 4.1 | Very Low | £287,991 |
| PorthmadogVery Low | 2.2 | 4.7 | Very Low | £218,266 |
| BontnewyddVery Low | 2.5 | 4.4 | Very Low | £251,579 |
| AberVery Low | 2.6 | 4.1 | Very Low | £215,083 |
| LlanllechidVery Low | 2.8 | 4.3 | Very Low | £324,791 |
| Y FelinheliVery Low | 3.4 | 4.8 | Very Low | £221,278 |
| CaernarfonVery Low | 3.6 | 4.9 | Very Low | £208,139 |
| PentirVery Low | 4.3 | 5.0 | Very Low | £273,757 |
| BangorVery Low | 4.6 | 5.1 | Very Low | £200,215 |
Levels in µg/m³, 2025 annual average.
How does air quality in Gwynedd compare with nearby areas?
Background NO₂ in Gwynedd compared with the 6 nearest other areas in Cymru / Wales.
Gwynedd vs Conwy
- Gwynedd
- NO₂ 2.3 µg/m³
- Conwy
- NO₂ 4.0 µg/m³
Open comparison
Gwynedd vs Ynys Môn / Isle of Anglesey
- Gwynedd
- NO₂ 2.3 µg/m³
- Ynys Môn / Isle of Anglesey
- NO₂ 3.3 µg/m³
Open comparison
Gwynedd vs Denbighshire
- Gwynedd
- NO₂ 2.3 µg/m³
- Denbighshire
- NO₂ 4.8 µg/m³
Open comparison
Gwynedd vs Ceredigion
- Gwynedd
- NO₂ 2.3 µg/m³
- Ceredigion
- NO₂ 2.5 µg/m³
Open comparison
Gwynedd vs Wrexham
- Gwynedd
- NO₂ 2.3 µg/m³
- Wrexham
- NO₂ 7.7 µg/m³
Open comparison
Gwynedd vs Flintshire
- Gwynedd
- NO₂ 2.3 µg/m³
- Flintshire
- NO₂ 7.9 µg/m³
Open comparison
Does this include busy roads?
No. These are background levels: yearly averages over 1 km squares, away from the immediate influence of roads. Right beside a busy road in Gwynedd, NO₂ can be much higher. Councils publish roadside monitoring in their annual air quality reports.
What else do people ask about Gwynedd?
More quick answers on house prices, sales, areas, green space, crime, air quality and listed buildings in Gwynedd.
- What is the average house price in Gwynedd?
- When did average house prices in Gwynedd reach their peak?
- How many properties are being sold in Gwynedd?
- What type of properties are sold in Gwynedd?
- What price range do most homes sell for in Gwynedd?
- What is the most expensive (and cheapest) area of Gwynedd?
- How many parks and green spaces are in Gwynedd?
- What is the crime rate in Gwynedd?
- How many listed buildings are in Gwynedd?
- How do Gwynedd house prices compare with another area?
Where does this data come from?
Price information is from HM Land Registry, location boundaries are from OpenStreetMap, and households and population are from Nomis Census 2021 postcode estimates (21 March 2021). Parks and green space are from OS Open Greenspace. Contains OS data © Crown copyright and database right 2026. Crime is from police.uk street-level data. Contains public sector information licensed under the Open Government Licence v3.0. Source: police.uk. Listed buildings and scheduled monuments are from Historic England and Cadw, and conservation areas from planning.data.gov.uk. Designated Historic Asset GIS Data, The Welsh Historic Environment Service (Cadw), licensed under the Open Government Licence. Air quality is from Defra modelled background pollution maps. Contains public sector information licensed under the Open Government Licence v3.0. Source: Defra modelled background pollution, 2025.
Last updated 11 November 2026 at 00:15 with the latest Land Registry data (September 2026). The Gwynedd dataset covers 6,531 postcodes.
Contains HM Land Registry data © Crown copyright and database right 2026. This data is licensed under the Open Government Licence v3.0.
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