UK Climate Rankings
A UK flood risk map ranking the 20 local authority areas with the highest percentage of postcodes containing at least one property in a higher flood-risk zone, based on national flood screening data from the Environment Agency, NRW and SEPA. Use the postcode search at the top of any page for an address-specific flood-risk band.
LocalRisk maps every UK mainland postcode to its property count by flood band using authoritative agency datasets: Environment Agency NaFRA2 (England), Natural Resources Wales 2023 Long Term Flood Risk Map (Wales), and SEPA's 2023 Flood Risk Management Maps (Scotland). Postcodes are aggregated to council area, and councils are ranked by the share of postcodes containing at least one property in the Higher or Very High band. Northern Ireland sits outside this ranking because DfI Rivers has not yet released property-level flood data compatible with the postcode-level methodology used here.
The Environment Agency defines its High band as a 3.3% or greater annual probability of flooding from rivers or sea, after accounting for existing flood defences. That works out to a 1-in-30 chance in any given year. SEPA and NRW use compatible methodologies. LocalRisk's own scale subdivides the agency High band: postcodes where over 90% of properties are in the EA High classification fall into "Very High"; the rest fall into "Higher". A property in a Higher-band postcode runs at least three times the national average long-term flood probability, though the specific risk varies by exact location within the postcode area.
Around 1 in 6 properties in England sits in some level of flood risk per Environment Agency figures. That national average hides very different local realities. Low-lying coastal councils in Lincolnshire and Somerset carry exposure well above the national average. Inner London boroughs cluster lower because high-rise property forms reduce per-postcode flood density and the Thames Barrier protects the tidal stretch. A single percentage at council level rolls up tidal, fluvial, and surface-water risk into one comparable number, so a home buyer or local journalist can see at a glance which areas warrant deeper investigation.
This list covers fluvial (river), tidal, and coastal flood risk. It does not include groundwater flooding, which the Environment Agency tracks separately and which can affect properties miles from any visible watercourse. Reservoir failure risk also sits outside the dataset. For an address-specific picture covering all five flood sources, use the Environment Agency's check-for-flooding service for England, SEPA's Flood Maps for Scotland, or NRW's Flood Map for Planning for Wales.
A postcode falls into the Higher or Very High band when at least one property within it has a 3.3% or greater annual probability of flooding from rivers or the sea, accounting for existing flood defences. That equates to a 1-in-30 chance in any given year. The Environment Agency, SEPA and NRW all use this same threshold as the High band in their primary flood maps. LocalRisk subdivides this into Higher and Very High based on the share of in-postcode properties that hit the threshold.
Northern Ireland flood data comes from DfI Rivers, which has not yet released property-level flood data we can integrate into our postcode-level ranking. Heat, air quality, and subsidence data for Northern Ireland are available on individual postcode pages. We will add Northern Ireland flood ranking once DfI Rivers makes a compatible dataset available.
We refresh the ranking every quarter from the underlying postcode data. The agency datasets themselves update on different cycles: Environment Agency NaFRA in late autumn each year, SEPA's Flood Risk Management Maps every six years (latest 2023), NRW's Long Term Flood Risk Map periodically. New flood defences and major data revisions can shift council positions between refreshes.
No. The ranking shows the share of postcodes in a council that contain at least one Higher-risk property, not the certainty that any specific property will flood. A council near the top of the list can still have many low-flood-risk areas within it. For an address-specific picture, check the Environment Agency's check-for-flooding service (England), SEPA's Flood Maps (Scotland), or NRW's Flood Map for Planning (Wales). The LocalRisk postcode page gives the postcode-level band alongside other climate risks.
Several factors push major cities lower. Many sit on higher ground or have invested in flood defences. London is protected on the tidal stretch by the Thames Barrier. The councils at the top of this ranking have a high share of properties on river floodplain, near tidal estuaries, or in low-lying coastal areas. Property-density mix also dilutes flood exposure per postcode in dense urban cores.