Harrow Rainfall ForecastUnited KingdomSEGreater LondonHarrowToday 15 May75%Sat 16 May55%Sun 17 May50%Mon 18 May60%Tue 19 May80%Wed 20 May10%Harrow rainfall forecast issued today at 7:39 am. Next forecast at approx. 9:39 pm.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast Met Office Rain Today Real-Time Chenies (Hertfordshire) RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads