A Flood Alert was issued for Portsmouth in Portsmouth on 25th October 2026. Affected watercourses included the The Solent, Portsmouth Harbour, Langstone Harbour.
During this event, FloodRadar monitoring gauges recorded notable rises. The Tide at Portsmouth rose 4.21m, peaking at 2.42m, while the River Alver at Browndown climbed 0.66m.
Environment Agency advice issued
High tides on Monday may lead to flooding. Flooding is possible for 1 hour either side of Monday morning's tide at 11:00 on 26/10/2026. The weather increases tide table values by 0.44 m. Total forecast tide is 5.37 metres Chart Datum (2.64 mAOD) at Portsmouth. Strong Southerly Force 5 wind. In Old Portsmouth, the tide may just exceed the top of the main slipway which will cause minor road flooding in East Street and to the boat yards at The Camber. Spray overtopping of defence walls at Southsea promenade and Eastern road is also expected. To protect property in Old Portsmouth, tidal defence
Monitoring gauges during this event
| Station | River | Rise | Peak |
|---|---|---|---|
| Portsmouth | Tide | +4.21m | 2.42m |
| Browndown | River Alver | +0.66m | 1.19m |
| Havant | Hermitage Stream | +0.41m | 5.49m |
| Denmead | River Wallington | +0.37m | 33.71m |
| Crosslands Drive | River Lavant | +0.36m | 0.49m |
| Emsworth | West Brook | +0.34m | 2.09m |
| North Fareham weir | River Wallington | +0.22m | 0.47m |
| West Street | River Lavant | +0.18m | 7.22m |
| Westbourne | River Ems | +0.06m | 0.13m |