NW4: 33 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in NW4, NW4 3BR, stands 33 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, NW4 4QX, stands 82 m above it.
- Ground at eight in ten of its postcodes: between 50 m and 80 m, measured from Ordnance Datum; the middle one stands at 66 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- In Barnet.