As of mid-February, all five of the Great Lakes are “officially” frozen over. In actuality, they were 90% ice covered, but when they hit that level, the people in charge of observing Great Lakes ice conditions proclaim them to be totally frozen. The last time the lakes were frozen completely was in 1994.
Few lakes in the upper Midwest completely freeze in the winter. Springs, muskrats, wildfowl, stream inflows, pressure ridges and other factors often produce areas with thin ice or even open water.
In the Great Lakes, unfrozen areas can be the result of currents as in the Straights of Mackinaw, St. Mary's River, Detroit River, Niagara River and a few others. Industries and lake shore power plants discharge heated water in other areas. There can be wind-driven openings in the ice similar to pressure ridges that occur on inland lakes.
The U.S. Coast Guard operates a fleet of ice-breaker vessels on the Great Lakes. There's our tax dollars at work! In some areas tug boats and other vessels do ice breaker duty to keep industrial harbors in action.
There are two silver linings to the frozen Great Lakes. Winter evaporation from unfrozen surface water in mild winters is one factor creating what’s become chronic, even record low lake levels. Related to the evaporation from the unfrozen lakes is, once the lakes are frozen, the lake effect snow machine is shut down. The upper Midwest is getting enough snow to satisfy most people without the lake snow this winter.
Will this have an affect on the fishing next season? Maybe a late start to the action.... Maybe it will drive more fish down to MY end of the lake.... Hope so! There's only one way to find out. The fun way. Let's go fishing !