Portsmouth Harbour - HMNB Portsmouth Rainfall ForecastUnited KingdomSEHampshirePortsmouth Harbour - HMNB PortsmouthToday 28 Sep20%Tue 29 Sep95%Wed 30 Sep90%Thu 1 Oct40%Fri 2 Oct10%Sat 3 Oct10%Sun 4 Oct5%1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Portsmouth Harbour - HMNB Portsmouth rainfall forecast issued today at 7:09 am. Next forecast at approx. 9:09 pm. Rainfall Rainfall AccumulationDean Hill (Wiltshire) RadarGet WillyWeather+ to remove ads