Portsmouth Harbour - HMNB Portsmouth Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - HMNB PortsmouthToday 2 Apr10%Fri 3 Apr10%Sat 4 Apr5%Sun 5 AprNo RainMon 6 Apr55%Portsmouth Harbour - HMNB Portsmouth rainfall forecast issued today at 6:31 am. Next forecast at approx. 8:31 pm.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time National RadarNational SatelliteNational SynopticGet an account to remove ads