Dear Tom,
There is a lot more ice on Lake Michigan now than in January. Is it unusual for the lake to be this icy in March? It seems to me there should be more ice in January, the coldest part of the winter.
–James Kohlmann
Dear James,
It’s true that winter’s coldest temperatures occur in mid-January and readings gradually moderate after that. Chicago’s normal daily temperatures hit bottom at 21 degrees during Jan. 13-18, then begin rising.
However, normal temperatures, though rising, remain below freezing until Feb. 28 (31 degrees.) The normal temperature rises to 32 degrees on March 1 and to 33 degrees on March 3. That means ice coverage on Lake Michigan increases through the end of February.
The Great Lakes Environmental Research Laboratory in Ann Arbor, Mich., provides these statistics: On average, ice covers 18 percent of Lake Michigan by mid-January, 24 percent by mid-February and 45 percent on March 1, which is the peak coverage. ———-
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