Portsmouth Harbour - HMNB Portsmouth Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - HMNB PortsmouthToday 31 Jan15%Sat 1 Feb10%Sun 2 Feb5%Mon 3 Feb5%Tue 4 Feb20%Wed 5 Feb5%Thu 6 Feb5%Portsmouth Harbour - HMNB Portsmouth rainfall forecast issued today at 12:38 pm. Next forecast at approx. 2:38 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