River Tamar - St John's Lake Entrance Rainfall ForecastUnited KingdomSWCornwallRiver Tamar - St John's Lake EntranceToday 13 May90%Thu 14 May65%Fri 15 May5%Sat 16 May40%Sun 17 May30%Mon 18 May50%Tue 19 May50%River Tamar - St John's Lake Entrance rainfall forecast issued today at 1:38 pm. Next forecast at approx. 3:38 am.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