With the exception a few lakes in and around the boundary waters, the lakes in Minnesota are now free of ice. With April temperatures averaging 1 to 2 degrees below average, most of the lakes in the northern half of Minnesota became ice-free about 6 to 10 days later than normal. According to the Minnesota Climatology Working Group from the University of Minnesota, Detroit Lake was reported ice free on April 26. Detroit Lake with 116 years of records has an average ice-out date of April 20.
Another lake with a long history of records is Lake Osakis with 142 years of data. Lake Osakis average ice out through the years is April 16 with ice-out this year occurring on April 20.
Other notable lakes include Otter Tail with an ice out April 26, 11 days later than average, West Battle on April 26, 10 days later than average and Sallie on April 29, which was 11 days past average.
You can find more lakes and data here: