Portsmouth Harbour - Portchester Castle Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - Portchester CastleToday 15 Apr15%Wed 16 Apr10%Thu 17 Apr10%Fri 18 Apr25%Sat 19 Apr20%Sun 20 Apr15%Mon 21 Apr15%Portsmouth Harbour - Portchester Castle 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