SM6: 19 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in SM6, SM6 7BQ, stands 19 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, SM6 0SW, stands 100 m above it.
- Ground at eight in ten of its postcodes: between 27 m and 80 m, measured from Ordnance Datum; the middle one stands at 54 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- In Sutton.