Merthyr Tydfil, Trelewis
CF46 5AR in Trelewis has a Low flood risk. Heat risk is Lower, with a median (50th percentile) of 12 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 5.1 μg/m³, above the WHO annual guideline of 5 μg/m³ (Defra UK-AIR). Ground conditions are Low risk, with Sandstone geology; shrink-swell risk is classed as improbable (BGS GeoSure).
Flood risk at CF46 5AR is rated Low, based on Natural Resources Wales flood mapping.
Natural Resources Wales flood zone data shows low flood risk for CF46 5AR in Trelewis. 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.
Air quality at CF46 5AR 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 CF46 5AR as Sandstone, 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.
This LocalRisk report for CF46 5AR 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 Merthyr Tydfil and is updated as new official datasets are published.
Merthyr Tydfil has a valley town setting at the head of the Taff valley in the South Wales Valleys and experiences cool, wet winters and mild summers, shaped by its upland position and valley topography.
Climate risk can change street by street, so it is worth checking neighbouring postcodes too. The full risk report for CF46 5AA is at localrisk.co.uk/postcode/CF465AA, and you can compare CF46 5AR side by side with any UK postcode at localrisk.co.uk/compare.