Johnstone Castle Rainfall ForecastUnited KingdomSTRenfrewshireJohnstone CastleToday 16 Jan75%Sat 17 Jan15%Sun 18 Jan15%Mon 19 Jan40%Tue 20 Jan15%Wed 21 Jan40%Thu 22 Jan15%Johnstone Castle rainfall forecast issued today at 12:37 pm. Next forecast at approx. 2:37 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