LL35 0EA - Flood, Heat, Air & Subsidence Risk - Nefyn

Gwynedd, Nefyn

LL35 0EA in Nefyn has a Very 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 Quaternary Marine/Estuarine Sand And Silt geology; shrink-swell risk is classed as improbable (BGS GeoSure).

• Flood: Flood risk is minimal in this area.
• Heat: Projected 8 days above 25°C per year, 2021-2040 average (Met Office UKCP18, 50th percentile under RCP8.5).
• Air quality: PM2.5 4.3 µg/m³ - within the WHO annual guideline of 5 µg/m³ (Defra UK-AIR).
• Ground: BGS data: Quaternary Marine/Estuarine Sand And Silt geology. Shrink-swell risk classed as improbable (British Geological Survey).
• Coastal erosion: NCERM data: coastal erosion zone 171m from this postcode. Erosion risk: very high.

Flood risk at LL35 0EA is rated Very Low, based on Natural Resources Wales flood mapping.

Air quality at LL35 0EA 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.

BGS GeoSure data classes the underlying soil at LL35 0EA as Quaternary Marine/Estuarine Sand And Silt, 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.

The nearest projected coastal erosion zone to LL35 0EA is 171 m away (NRW NCERM No Active Intervention - Short-term (2005-2025) mapping) and the postcode is in the very high coastal erosion risk band. Coastal erosion risk varies along the shoreline depending on local geology, sea defences and Shoreline Management Plan policy. For properties near the coast, a specialist coastal erosion risk assessment is recommended.

This LocalRisk report for LL35 0EA 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.

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.

Natural Resources Wales flood zone data shows very low flood risk for LL35 0EA in Nefyn. 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.

Practical check: The nearest projected erosion zone is 171m away - check the Shoreline Management Plan policy for this stretch and whether the property is within 100 years of the erosion line. These are postcode-level indicators - conditions vary between individual properties.