NW3: 25 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in NW3, NW3 3QE, stands 25 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, NW3 6RF, stands 128 m above it.
- Ground at eight in ten of its postcodes: between 49 m and 110 m, measured from Ordnance Datum; the middle one stands at 70 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- Mostly in Camden; partly in Barnet.