Portsmouth Harbour - Portchester Lake Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - Portchester LakeToday 19 Dec5%Sat 20 Dec55%Sun 21 Dec70%Mon 22 Dec10%Tue 23 Dec15%Wed 24 Dec15%Portsmouth Harbour - Portchester Lake rainfall forecast issued today at 6:36 am. Next forecast at approx. 8:36 pm.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