St John Rainfall ForecastUnited KingdomSWCornwallSt JohnToday 4 Oct20%Mon 5 Oct20%Tue 6 Oct20%Wed 7 Oct15%Thu 8 Oct60%Fri 9 Oct60%Sat 10 Oct15%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 7:08 am. Next forecast at approx. 9:08 pm. Rainfall Rainfall AccumulationPredannack (Cornwall) RadarGet WillyWeather+ to remove ads