Alton Rainfall ForecastUnited StatesILMadison CountyAltonToday 18 Apr35%Sat 19 Apr100%Sun 20 Apr85%Mon 21 Apr90%Tue 22 Apr5%Wed 23 Apr25%Thu 24 Apr45%Alton rainfall forecast issued today at 7:04 pm. Next forecast at approx. 9:04 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast NOAA Rain Today Real-Time St Louis RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads