Actually, ever since climatologists have kept records on this topic, it’s varied quite a bit.The earliest freeze on record was November 25th; the latest was January 30th.
Each year, the Clean Lakes Alliance sponsors a contest. This year, the person with the best guess as to when the lake will freeze over wins a $1000 gift card to Lands End.
Have a guess? Enter and check out all the rules here.
(Above picture by Kitty Dunn, and yes, she knows it’s Monona Bay, not Lake Mendota).