What is lake ice in and ice out? Typically, the lake ice in date is when the entire lake freezes over for the first time and remains frozen over during the remainder of winter until ice out occurs. Lake ice out is the annual date in the spring when the ice breaks up and winter ice cover leaves the lake. Ice in and ice out definitions for individual lakes can vary over time and between observers. You may consider ice out when you can navigate from point A to point B with ice still visible in certain areas or you may consider ice out to be when the lake is completely free of ice. Feel free to include your observations in the observations section to help us better understand ice in and ice out on your lake.