Johnstone Castle Rainfall ForecastUnited KingdomSTRenfrewshireJohnstone CastleToday 20 Apr55%Tue 21 Apr55%Wed 22 Apr5%Thu 23 AprNo RainFri 24 AprNo RainSat 25 Apr5%Sun 26 Apr35%Johnstone Castle rainfall forecast issued today at 7:37 pm. Next forecast at approx. 9:37 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Holehead (Stirling) RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads