Flood Risk Guide · London
Flood risk in London
Know My Postcode · 2026-04-12 · Environment Agency data
London has significant flood risk in many areas, particularly along the Thames and its tributaries. Before buying or renting in London, always check the flood risk for the specific postcode — not just the general area.
Higher flood risk areas in London
- Twickenham and Richmond riverside
- Hammersmith and Chiswick
- Wandsworth and Battersea riverside
- Bermondsey and Rotherhithe
- Isle of Dogs
Lower flood risk areas in London
- Most of north London (Camden, Islington, Hackney)
- Most of south London away from the Thames
- West London away from rivers
Flood defences in London
The Thames Barrier protects central London from tidal flooding. However, surface water flooding remains a risk across many London postcodes.
Understanding flood zones
- Zone 1 — Low risk: Less than 0.1% annual probability of flooding. Most properties fall here
- Zone 2 — Medium risk: 0.1% to 1% annual probability. Extra checks recommended before buying
- Zone 3 — High risk: Greater than 1% annual probability. Mortgage and insurance can be affected
Always check both river/coastal flood risk AND surface water flood risk for the most complete picture.