River Tamar - St John's Lake Entrance Rainfall ForecastUnited KingdomSWCornwallRiver Tamar - St John's Lake EntranceToday 3 Aug55%Mon 4 Aug85%Tue 5 AugNo RainWed 6 Aug5%Thu 7 Aug40%Fri 8 Aug5%Sat 9 Aug5%River Tamar - St John's Lake Entrance rainfall forecast issued today at 7:36 am. Next forecast at approx. 9:36 pm.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Predannack (Cornwall) RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads