× Expand Kristian Knutsen Lake Mendota (as seen near Maple Bluff) is now frozen. × I arrived at the office this morning to find a waiting email message from Lyle Anderson of the As with Lake Monona, which froze on Thursday, Jan. 18, this is the second-latest freeze date for Lake Mendota in 150 years of freeze-thaw record-keeping. The mark for latest freeze on both lakes is Jan. 30, set in 1932. The clock now starts ticking on the records for shortest duration of ice coverage on each lake. The mark for Mendota is 21 days, during the winter of 2001-02. Monona's shortest freeze was 49 days, during the winter of 1997-98.