According to an analysis by NOAA's Great Lakes Environmental Research Laboratory (NOAA/GLERL), ice covered 91 percent of the Great Lakes on March 4, 2014. In records dating to 1973, only February 1979 (94.7 percent peak) had a greater ice coverage.
Only a small area of southern Lake Michigan and much of western and central Lake Ontario have significant ice-free stretches, according to the March 4 NOAA/GLERL analysis.
About 95 percent of Lake Superior, just under 96 percent of Lake Huron, 95 percent of Lake Erie, and almost 92 percent of Lake Michigan is ice-covered.
The ice coverage has set an All-Time March record, topping March ice cover in the previous two standard-bearing years, 1979 and 1994:
March 5, 1979: 75.98 percent
March 4, 1994: 85.78 percent