Portsmouth Harbour - Portchester Castle Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - Portchester CastleToday 19 Mar20%Wed 20 Mar5%Thu 21 Mar15%Fri 22 Mar20%Sat 23 Mar35%Sun 24 Mar10%Portsmouth Harbour - Portchester Castle rainfall forecast issued today at 12:44 am. Next forecast at approx. 2:44 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 an account to remove ads