St John Rainfall ForecastUnited KingdomSWCornwallSt JohnToday 26 Apr85%Sat 27 Apr35%Sun 28 Apr15%Mon 29 Apr75%Tue 30 Apr80%Wed 1 May15%St John rainfall forecast issued today at 7:38 am. Next forecast at approx. 9:38 pm.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Predannack (Cornwall) RadarNational SatelliteNational SynopticGet an account to remove ads