River Tamar - St John's Lake Entrance Rainfall ForecastUnited KingdomSWCornwallRiver Tamar - St John's Lake EntranceToday 28 Sep55%Tue 29 Sep95%Wed 30 Sep45%Thu 1 Oct10%Fri 2 Oct30%Sat 3 Oct35%Sun 4 Oct10%1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time River Tamar - St John's Lake Entrance rainfall forecast issued today at 7:10 pm. Next forecast at approx. 9:10 am. Rainfall Rainfall AccumulationPredannack (Cornwall) RadarGet WillyWeather+ to remove ads