How does the lake freeze?

In the fall, when water cools, it becomes more dense and sinks to the bottom of the lake. Water is “heaviest” at 39 degrees F. As winter nights cool the water from 39 degrees down to 32 degrees, it expands and freezes! Expanded, frozen water (ice) is less dense, and lighter, so it floats! The fact that ice forms from the top down is lucky for fish and lucky for us – the ice acts as an insulator; and the heavier water at the bottom remains in its liquid form.