Following the coldest April on record throughout all of Minnesota, that has extended the period of ice cover on many of the lakes in the state. According to the Hennepin County Sheriff’s Office water patrol, Lake Minnetonka, which is about an 14,500-acre lake, is officially ice free, as of May 5th. The Minnesota Department of Natural Resources defines what an ice out is: “[It] occurs when the lake is completely free of ice. Or, it may be when it is possible to navigate from point A to point B. Ice out may also be when a lake is 90 percent free of ice.” This is the situation on Lake Minnetonka, despite some lingering ice.
This date ties the record for the latest ice-out on record for this lake, which was set in 1857. This comes after the average last date of ice cover on the lake, which is April 14th. According to the Freshwater Society in St. Paul and StarTribune, “in the past 20 years, 14 ice-outs have been earlier than the median date, and six have been on it or later.”
For the rest of the state of Minnesota, most small lakes are now ice-free, but based on the MODIS satellite image below, captured on May 6th, you can still see ice cover on the larger lakes. Due to the greater surface area, ice takes a longer time to melt. We also compared the ice cover on May 6th of this year to that of last year.