POSTCODE AREA CLIMATE RISK
SN11 is a UK postcode district covering part of Calne, Wiltshire. LocalRisk has flood, heat, air and ground-stability data for 769 postcodes in SN11.
16.6% of postcodes in SN11 fall into the Environment Agency's high flood-risk band - above the UK average of about 7%. The band reflects the highest flood risk within each postcode; some properties may face little or no direct flood risk. Two postcodes a few streets apart can land in different bands; what drives the gap is elevation, distance to the nearest watercourse, and how the surrounding drainage performs in heavy rain. The postcode list below links to the full address-level reading for each postcode in SN11.
Met Office UKCP18 projections (50th percentile) estimate around 27 days above 25°C per year for the area covering SN11, averaged over the 2021-2040 period under the RCP8.5 high emissions scenario. These are probabilistic projections - the full range of modelled outcomes is wide and lower emissions scenarios would produce lower figures.
Annual mean PM2.5 for the council area covering SN11 is 6.0 µg/m³ - close to the World Health Organisation guideline of 5 µg/m³. Postcodes within 200 metres of an A-road or major junction routinely run higher during weekday rush hours than residential streets two roads back.
Ground stability in SN11 follows the underlying geology more than the postal boundary. The British Geological Survey GeoSure dataset maps clay shrink-swell risk on a 50-metre cell, and properties on the same street can sit in different bands where a clay seam ends mid-road. A postcode-level check picks up that variation.
Flood risk - postcodes in SN11
Environment Agency NaFRA2 data. Postcode-level. Search below for your exact risk.