St John Rainfall ForecastUnited KingdomSWCornwallSt JohnToday 12 Aug5%Thu 13 Aug5%Fri 14 Aug5%Sat 15 Aug5%Sun 16 Aug15%Mon 17 Aug40%1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time St John rainfall forecast issued today at 1:08 am. Next forecast at approx. 3:08 pm. Rainfall Rainfall AccumulationPredannack (Cornwall) RadarGet WillyWeather+ to remove ads