Does Portsmouth flood?

Flood warnings in force near Portsmouth

• Flood warning — South Hayling and South Eastoke seafront
  Flooding is expected for 2 hours either side of Monday morning's tide at 11:02 on 26/10/2026 8.6 km
• Flood alert — Portsmouth
  Flooding is possible for 1 hour either side of Monday morning's tide at 11:00 on 26/10/2026 1.2 km
• Flood alert — Fareham to Portchester
  Flooding is possible for 1 hour either side of Monday morning's tide at 11:00 on 26/10/2026 5.7 km
• Flood alert — Langstone to Emsworth Harbour
  Flooding is possible for 1 hour either side of Monday morning's tide at 11:00 on 26/10/2026 9.1 km

From the Environment Agency (England). Always check the GOV.UK Check for Flooding service or call Floodline on 0345 988 1188.

What the Environment Agency's rivers-and-sea flood-risk data says about Portsmouth

Ordnance Survey places 795 postcodes in Portsmouth in the Environment Agency's rivers-and-sea flood-risk dataset (Risk of Flooding from Rivers and Sea). Each postcode is counted once, under the worst band any of its properties reaches; together they hold 12,657 properties in the EA dataset's likelihood bands.

This dataset covers flooding from rivers and the sea only — one of five flood sources. Surface water, groundwater, sewers and reservoirs are assessed separately, so a postcode missing from it is not proof that a place cannot flood. The band describes the land around properties (allowing for defences), not any single address and not today's conditions.

Rivers and live river levels near Portsmouth

Environment Agency gauges within 10 km of Portsmouth watch River Alver, Hermitage Stream, River Lavant, River Wallington.

• Portsmouth Tidal
  Tide · 3.0 km away 0.37 mAOD
  rises and falls with the tide · 35 min ago
• Browndown
  River Alver · 7.0 km away 1.20 m
  normal range · 35 min ago
• Havant
  Hermitage Stream · 7.8 km away 5.13 mAOD
  normal range · just past its peak · 35 min ago
• West Street
  River Lavant · 7.9 km away 7.07 mAOD
  normal range · steady · 35 min ago
• North Fareham weir Structure
  River Wallington · 8.7 km away 0.22 m
  controlled by a sluice or weir · 35 min ago
• Crosslands Drive
  River Lavant · 8.9 km away 0.16 m
  normal range · falling · 35 min ago
• Denmead
  River Wallington · 9.2 km away 33.48 mAOD
  normal range · rising · 35 min ago

Distances are from the middle of Portsmouth's at-risk postcodes. Tidal and structure gauges are shown as readings only — the tide and sluice gates move them, not floods. A gauge with no recent reading shows no level.

Flood warning areas near Portsmouth

31 Environment Agency flood warning areas lie within 10 km of Portsmouth. The EA has issued 531 flood warnings and alerts for them since 2006, most recently on 26 Oct 2026.

• Coastal area around Portsmouth
  75 warnings and alerts since 2006, latest Oct 2026 1.2 km
• Tidal areas including Tipner, Stamshaw, and the Commercial Docks
  no warning on record since 2006 1.5 km
• Tidal areas of Eastern Portsmouth, including Anchorage Park, Baffins, Milton, and Eastney
  no warning on record since 2006 1.9 km
• Tidal areas at Hilsea
  no warning on record since 2006 2.3 km
• Coast at Old Portsmouth
  2 warnings and alerts since 2006, latest Apr 2024 2.6 km
• Coast at Southsea
  no warning on record since 2006 3.1 km
• Tidal areas from North Harbour to Brockhampton, including Port Solent, Horsea Island, Highbury and Farlington Marshes
  no warning on record since 2006 4.7 km
• Coastal area from Port Solent to Brockhampton including Farlington Marshes
  11 warnings and alerts since 2006, latest Apr 2024 4.7 km
• Tidal areas of Portchester
  2 warnings and alerts since 2006, latest Apr 2024 4.8 km
• Areas inland of South Hayling seafront including Sea View and Mengham north of seafront. Westfield, Sinah Common and Sinah Lane
  2 warnings and alerts since 2006, latest Apr 2024 5.1 km
• Tidal areas at Gosport, including Clayhall, Forton, Priddy's Hard, and the Town Centre
  1 warning or alert since 2006, latest Apr 2024 5.4 km
• Coastal area from Fareham to Portchester
  53 warnings and alerts since 2006, latest Oct 2026 5.7 km

Recorded floods near Portsmouth

Floods whose mapped extent (EA Recorded Flood Outlines) reached within ~5 km of Portsmouth, most recent first. Records, not floods: no outline on the record is not evidence a place has not flooded. See them on the map →

• 10 Mar 2008 — 10/03/2008 Town Quay Sea
• 10 Mar 2008 — 10/03/2008 Bath Square Sea
• 10 Feb 1977 — 10/02/1977_Bedhampton Brook_Bedhampton Ordinary watercourse

Rainfall near Portsmouth

Portsmouth gets about 752 mm of rain a year on average (wettest month November, 88 mm; driest May, 42 mm). That is 35% drier than the UK as a whole, which averages 1,163 mm a year. Source: Met Office HadUK-Grid 1991–2020 (5 km grid), 2.5 km from the place centre.

The nearest rain gauge, Rainfall station (3.8 km away), recorded 2.6 mm in the last 24 hours and 94.3 mm in the last 7 days (latest reading 35 min ago).

At-risk postcodes in Portsmouth

Every postcode Ordnance Survey places in Portsmouth that appears in the EA's rivers-and-sea dataset, worst band first. Each links to its own flood-risk page.

High likelihood (248)

Medium likelihood (72)

Low likelihood (301)

Very low likelihood (174)

Postcode districts

Sources

FloodRadar summarises public flood data. It is not a flood-risk survey of any property, and it does not replace official GOV.UK flood warnings or the GOV.UK long-term flood risk service.