LOCATION

LL41 3AN - Flood, Heat, Air & Subsidence Risk - Llan Ffestiniog

Gwynedd, Llan Ffestiniog

Flood: LowHeat: LowerAir quality: LowGround: Low

Climate risk summary for LL41 3AN

LL41 3AN in Llan Ffestiniog has a Low flood risk. Heat risk is Lower, with a median (50th percentile) of 8 days above 25°C per year, averaged over the 2021-2040 period under the RCP8.5 high emissions scenario (Met Office UKCP18). Air quality is Low at PM2.5 4.3 μg/m³, within the WHO annual guideline of 5 μg/m³ (Defra UK-AIR). Ground conditions are Low risk, with Sandstone And Mudstone geology; shrink-swell risk is classed as improbable (BGS GeoSure).

How does LL41 3AN compare with the rest of the UK?

  • Air pollution: cleaner than 95% of councils
  • Heat risk: cooler than 85% of councils
  • Subsidence risk: lower risk than 58% of postcodes

What is the flood risk in LL41 3AN?

Flood risk at LL41 3AN is rated Low, based on Natural Resources Wales flood mapping.

Natural Resources Wales flood zone data shows low flood risk for LL41 3AN in Llan Ffestiniog. The band reflects the highest flood risk within the postcode; some properties within this postcode may face little or no direct flood risk. For a specific property, a conveyancing search will confirm the exact flood zone position.

How is the air quality in LL41 3AN?

Air quality at LL41 3AN is rated Low, based on Defra UK-AIR annual mean PM2.5 data. Fine particulate matter (PM2.5) comes primarily from road traffic, industry, and domestic burning. Long-term exposure above the WHO guideline of 5 µg/m³ is linked to respiratory and cardiovascular health risks. Buyers and renters in higher air quality risk areas may wish to consider whether the property is near busy roads or industrial sources.

Is subsidence a risk at LL41 3AN?

BGS GeoSure data classes the underlying soil at LL41 3AN as Sandstone And Mudstone, with shrink-swell hazard rated improbable (subsidence risk band: Low). Soil type and shrink-swell behaviour drive subsidence claims following dry summers; recent ABI data shows insurer payouts rose sharply after the 2022 and 2025 hot summers. A structural survey is the reliable way to assess ground risk for a specific property.

Where does this data come from?

This LocalRisk report for LL41 3AN draws on four official UK open data sources: Natural Resources Wales flood mapping, Met Office UKCP18 climate projections, Defra UK-AIR PM2.5 monitoring, and British Geological Survey GeoSure subsidence mapping. Risk ratings are a screening tool, complementing - not replacing - the searches and surveys ordered as part of a property transaction. Data covers Gwynedd and is updated as new official datasets are published.

About the Gwynedd area

Gwynedd has a predominantly upland and coastal setting with mountains, river valleys and dispersed settlements and experiences cool, wet winters and mild summers, shaped by Atlantic weather and steep catchments.

Climate risk can change street by street, so it is worth checking neighbouring postcodes too. The full risk report for LL41 3AA is at localrisk.co.uk/postcode/LL413AA, and you can compare LL41 3AN side by side with any UK postcode at localrisk.co.uk/compare.