In Minnesota even with a "normal" winter, ice on the lake can vary greatly on the same lake and become unpredictable. Everyone who ventures out on the ice needs to use extreme caution, check locally before heading out on any lake and avoid nighttime travel once lake closings have been issued.
Credit: Department of Natural Resource Website, "Department of Natural Resources" Lake Closings.
Ice Out Information
On Lake Minnetonka, the ice is designated as "out" when it is possible to make way by small boat from any one shore to any other shore through any passage on the lake. Ice-out dates have been determined by using this method since 1968.
Previous methods included: When ice was 90% gone, when a boat could circle Big Island, when a boat could travel between Wayzata and Excelsior, when a car fell through the ice, or by visual observations from limited lake locations.
Credit: Freshwater Society Website, "Freshwater Society" Lake Minnetonka Ice-Out Dates: 1855 to 2003.