W1S: 10 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in W1S, W1S 4EF, stands 10 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, W1S 1JJ, stands 20 m above it.
- Ground at eight in ten of its postcodes: between 19 m and 24 m, measured from Ordnance Datum; the middle one stands at 21 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- In Westminster.