Ice out is based on the standards of the Gray Freshwater Biological Institute, which states a lake must be 90 percent free of ice and one must be able to drive a small boat from any one shore across to the other shore. Koronis was probably 90 percent ice free a few days earlier, but because the west bay of Lake Koronis was full of ice, one could not have driven a small boat from the Adams Landing across the lake until Sunday.
This year is the sixth earliest ice out since 1962. Koronis’ earliest ice-out was March 24, 1987, followed by March 27, 1981; March 31, 1968; April 2, 1973; and April 4, 1966. The ice-outs are based on records kept by Genevieve Koenig from 1962 to 1993 and the Press since then.