Does HA1 flood?

Yes — parts of the HA1 district carry real flood risk: 3 of its 4 at-risk postcodes reach the Environment Agency's High likelihood band. The HA1 postcode district covers Headstone, close to Pinner, North Harrow, Northolt, and surrounding villages in parts of England and Hertfordshire.

4 postcodes in the HA1 district appear in the Environment Agency's rivers-and-sea flood-risk dataset — worst bands: 3 high, 1 low. A postcode not listed here has no properties in any recorded risk band (which is good news, but never proof it cannot flood).

Free preview first · full report £19

Which HA1 postcodes are at risk?

HA1 4PD up to High HA1 4PE up to High HA1 4PJ up to High HA1 4PR up to Low

Rivers and flooding history near HA1

The rivers that matter here, each monitored live on FloodRadar:

Pinner, Eastcote Road on the River Pinn — 1.6 km away, highest on record 2.42m
Pinner, Moss Close on the River Pinn — 1.8 km away, highest on record 1.16m
Harrow, Village Way on the Yeading Brook — 1.8 km away, highest on record 1.48m
Pinner, Avenue Road on the River Pinn — 2 km away, highest on record 1.55m

317 official flood warnings and alerts have been raised within ~10 km of the district's centre since 2006 (25 at warning level or above), most recently 27 August 2026. Warnings cover flood areas, not individual addresses.

Recorded flood extents near the district (Environment Agency record):

June 2016 flooding — about 3.1 km from the centre
June 2016 flooding — about 2.9 km from the centre
June 2016 flooding — about 1.2 km from the centre
Winter 2013/2014 (2013) — about 36.1 km from the centre

🏠 Buying or renting in HA1? The full property flood-risk report covers any postcode here — the official likelihood band, every recorded flood nearby with distances, warning history year by year, how the local rivers behave, and an insurance outlook, print-ready for £19. See what's in the report →

Flood risk in nearby postcode districts

HA0 HA2 HA3 HA4 HA5 HA6 HA7 HA8

Band = the worst likelihood band of any property in that postcode (EA Risk of Flooding from Rivers & Sea, defence-adjusted, area-level). Check any postcode in detail — or get the full £19 property report — at the property flood-risk report. © Environment Agency copyright and/or database right 2025. All rights reserved. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, © NERC (CEH). © Crown Copyright and Database Rights 2025 OS AC0000807064. This product is produced in part from PAF® and Multiple Residence Data, the copyright in which is owned by Royal Mail Group Limited and/or Royal Mail Group plc. All rights reserved. Licence number AC0000807064.