Town CLIMATE RISK

Castlereagh Climate Risk Data

Castlereagh is a town in Antrim, within the Lisburn and Castlereagh council area. LocalRisk has flood, heat, air and ground-stability data for 1,516 postcodes in Castlereagh; 12 samples are linked at the foot of this page.

Postcode-level flood data for Castlereagh (DfI Rivers) is not yet integrated into LocalRisk. Northern Ireland uses DfI Rivers strategic flood maps, which we are working to add. To check individual property flood risk in Castlereagh today, use the NI Direct flood maps. Heat, air quality and subsidence data on this page are postcode-level.

Met Office UKCP18 projections estimate around 4 days above 25°C per year across the Lisburn and Castlereagh area for the 2021-2040 period - the central scenario under high emissions; lower-emissions paths give lower numbers. Heat exposure within Castlereagh itself is uneven: top-floor flats, west-facing terraces and properties without through-ventilation hold heat well into the night, while ground-floor homes near tree cover or open ground cool faster. The headline 4-day figure is an area average, not a property-level reading.

Annual mean PM2.5 across the Lisburn and Castlereagh area is 5.1 µg/m³ - close to the World Health Organisation guideline of 5 µg/m³. Within Castlereagh, readings are not flat: postcodes within 200 metres of an A-road or major junction routinely run 30-50% higher during weekday rush hours than residential streets two roads back. Defra's UK-AIR network supplies the underlying figure.

Ground stability in Castlereagh 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. Pre-1980 housing on clay-rich ground is the most exposed; properties on bedrock or well-drained sandy soils are typically lower-risk. A postcode-level check picks up that variation.

A free postcode check on LocalRisk covers up to six hazards for any address in Castlereagh: flood mapping (DfI Rivers data not yet integrated for Northern Ireland), BGS ground stability, Met Office heat projections, Defra PM2.5, plus coastal erosion and green-space access where relevant. The postcode list below opens an address-level report for each postcode in Castlereagh; the council link at the top of this page returns to the wider Lisburn and Castlereagh picture.