Southampton, Midanbury
SO18 1AH in Midanbury has a Very low flood risk - EA NaFRA2 data records no properties in a flood risk zone in this postcode. Heat risk is Medium, with a median (50th percentile) of 34 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 Medium at PM2.5 6.5 μg/m³, above the WHO annual guideline of 5 μg/m³ (Defra UK-AIR). Ground conditions are Low risk, with River Terrace Sand/Gravel geology; shrink-swell risk is classed as improbable (BGS GeoSure).
National comparison
Flood risk at SO18 1AH is rated Very Low, based on Environment Agency NaFRA2 modelling.
Heat risk at SO18 1AH is rated Medium, reflecting Met Office UKCP18 climate projections (50th percentile) for this area, averaged over the 2021-2040 period under the RCP8.5 high emissions scenario. These are probabilistic projections - the 50th percentile is the central estimate within RCP8.5; the full range of modelled outcomes is wide and lower emissions scenarios would produce lower figures. Higher summer temperatures increase cooling energy costs, affect comfort in poorly insulated or south-facing properties, and can accelerate shrinkage in clay soils beneath foundations. Properties built before 1980 without cavity wall insulation are typically most affected.
Air quality at SO18 1AH is rated Medium, 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 SO18 1AH as River Terrace Sand/Gravel, 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 SO18 1AH is 98 m away (Erosion projected by 2055 (no climate change uplift) - SMP policy: Hold The Line 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 SO18 1AH draws on four official UK open data sources: Environment Agency NaFRA2 flood modelling, 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 Southampton and is updated as new official datasets are published.
Southampton has a coastal city setting with estuaries, rivers and dense development around a major port and experiences cool, wet winters and mild summers, influenced by English Channel conditions and extensive hard surfacing.
Environment Agency flood zone data shows very low flood risk for SO18 1AH in Midanbury. EA NaFRA2 data shows no properties at flood risk in this postcode. 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: 34 hot days are projected (UKCP18 50th percentile, 2021-2040 average under RCP8.5) - check which rooms face south or west and whether the property has cross-ventilation or external shading. The nearest projected erosion zone is 98m 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.