Portsmouth Harbour - Portchester Lake Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - Portchester LakeToday 9 May15%Sun 10 May50%Mon 11 May15%Tue 12 May10%Wed 13 May20%Thu 14 May40%Fri 15 May30%Portsmouth Harbour - Portchester Lake rainfall forecast issued today at 1:38 pm. Next forecast at approx. 3:38 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Dean Hill (Wiltshire) RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads