Harrow on the Hill Rainfall ForecastUnited KingdomSEGreater LondonHarrow on the HillToday 29 Jun10%Mon 30 JunNo RainTue 1 Jul15%Wed 2 Jul30%Thu 3 Jul15%Fri 4 Jul10%Harrow on the Hill rainfall forecast issued today at 7:36 am. Next forecast at approx. 9:36 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