CF82 6AR - Flood, Heat, Air & Subsidence Risk - Ystrad Mynach

Caerphilly, Ystrad Mynach

Climate risk summary for CF82 6AR

CF82 6AR in Ystrad Mynach has a High flood risk. Heat risk is Lower, with a median (50th percentile) of 18 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 5.5 μg/m³, above the WHO annual guideline of 5 μg/m³ (Defra UK-AIR). Ground conditions are Low risk, with Glacial Till geology; shrink-swell risk is classed as improbable (BGS GeoSure).

• Flood: Plan with flood risk in mind for this area.
• Heat: Projected 18 days above 25°C per year, 2021-2040 average (Met Office UKCP18, 50th percentile under RCP8.5, 12 km grid - postcodes within the same grid cell share this value).
• Air quality: PM2.5 5.5 µg/m³ - above the WHO annual guideline of 5 µg/m³ (Defra UK-AIR PCM model, council-level average - every postcode in this council shows this value).
• Ground: BGS data: Glacial Till geology. Shrink-swell risk classed as improbable (British Geological Survey).

What is the flood risk in CF82 6AR?

Flood risk at CF82 6AR is rated High, based on Natural Resources Wales flood mapping.

Natural Resources Wales flood zone data places CF82 6AR in the high flood risk band. The band reflects the highest flood risk within the postcode; some properties within this postcode may face little or no direct flood risk. A formal flood risk search and review of buildings insurance availability is recommended before any property transaction in this area.

How is the air quality in CF82 6AR?

Air quality at CF82 6AR 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 CF82 6AR?

BGS GeoSure data classes the underlying soil at CF82 6AR as Glacial Till, 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 CF82 6AR 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 Caerphilly and is updated as new official datasets are published.

About the Caerphilly area

Caerphilly has an upland valley setting with towns spread along former industrial corridors and experiences cool, wet winters and mild summers, influenced by elevation and narrow catchments.

What should buyers and renters check in CF82 6AR?

Practical check: With 18 hot days projected (UKCP18 50th percentile, 2021-2040 average under RCP8.5), note which bedrooms face west (hottest in evening) and whether windows allow through-ventilation. These are postcode-level indicators - conditions vary between individual properties.

Climate risk can change street by street, so it is worth checking neighbouring postcodes too. The full risk report for CF82 6AA is at localrisk.co.uk/postcode/CF826AA, and you can compare CF82 6AR side by side with any UK postcode at localrisk.co.uk/compare.