Grand Portage Lake Rainfall ForecastUnited StatesWIIron CountyGrand Portage LakeToday 18 Apr75%Sat 19 Apr20%Sun 20 Apr10%Mon 21 Apr75%Tue 22 Apr30%Wed 23 Apr50%Thu 24 Apr20%Grand Portage Lake rainfall forecast issued today at 12:03 pm. Next forecast at approx. 2:03 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast NOAA Rain Today Real-Time Duluth RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads