Portsmouth Harbour - HMNB Portsmouth Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - HMNB PortsmouthToday 6 Jul45%Mon 7 Jul55%Tue 8 JulNo RainWed 9 JulNo RainThu 10 JulNo RainFri 11 JulNo RainPortsmouth Harbour - HMNB Portsmouth rainfall forecast issued today at 1:36 am. Next forecast at approx. 3:36 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