Portsmouth Harbour - HMNB Portsmouth Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - HMNB PortsmouthToday 17 May55%Mon 18 May90%Tue 19 May85%Wed 20 May45%Thu 21 May5%Fri 22 May5%Portsmouth Harbour - HMNB Portsmouth rainfall forecast issued yesterday at 7:36 pm. Next forecast at approx. 9:36 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