HA4: 28 m clear of the highest tide in the London Bridge ledgers

HA4 on the relief of London, with a tide staff: 28 m above the 1953 tide, the highest in the ledgers.

The lowest postcode in HA4, HA4 6UW, stands 28 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, HA4 6EY, stands 55 m above it.

Ground at eight in ten of its postcodes: between 36 m and 52 m, measured from Ordnance Datum; the middle one stands at 44 m.
None lies in the Environment Agency's Flood Zone 3 from the sea.
Mostly in Hillingdon; partly in Harrow.

Open HA4 on the map