why does water in the center of a lake freeze slower then the edge?

Answer 1

The center of a lake is generally (not always) the deepest point and it is as the deepest point where the water has to turn over the longest until it has all reached 32F. It is only at this point that a slight drop below 32 makes the water slightly less dense than the 32 degree water such that ice can form. It is for this reason that ice forms downward in a pond and not upward from the bottom.

Answer 2

the water in the middle is deeper. the water is cooled by evaporation and air temperature near the top, but this is offset by the (slightly) warmer water below. the more water you have to freeze, the slower it freezes. water in a lake does not freeze all the way to the bottom, except near the edge, no matter how cold it gets or all the fish would die. the same thing works in reverse in the summer. when you go into the lake, it's warm near the shore, but when you go out a bit more and the water is deeper, then it's colder.

Answer 3

Volume and density; that is, a thin layer freezes quickly where a thicker one takes longer. So the thinner layers at the edges freeze quick but as depth inceases so does thickness (density) of the layer and it takes longer to freeze.