Many of my calls right now are regarding ice conditions on Mille Lacs Lake and if we will have open water for Minnesota’s Walleye/Northern fishing opener on May 11th.
The definition of lake ice-out varies from lake to lake, and individual to individual. For some, ice-out occurs only when the lake is completely free of ice. For others, ice-out is defined as the moment when navigation is possible from point A to point B. And yet for others, ice-out is when 90 percent of the lake is ice free. Due to the variable definitions of this rather subjective observation, the State Climatology Office attempts to contact the same individuals each year to maintain a consistent record.
In addition to differences in ice-out observation techniques, the variable period of record and variable length of record makes lake to lake comparisons of averages and extremes problematic. Differences in lake size, lake depth, and lake geometry also generate a large amount of variability among lakes in close proximity.
Mille Lacs is a very large lake and wind greatly affects how the ice goes off. We always hope it departs quietly but it can be a spectacular site watching it shift and move and pile up on the shorelines, destroying much of what’s in it’s path. Check out this video for scenes of past year ice outs and the havoc it can reek!