Answer:
Generally the ice should be more than 4 inches thick to skate on it safely. However, the ice thickness is not always even and there can be thin spots, especially near springs or near river inlets or outlets. Most lakes and ponds don't completely freeze because the ice (and eventually snow) on the surface acts to insulate the water below. Our winters aren't long or cold enough to completely freeze most local water bodies. This process of lakes turning over is critically important to the life in the lake.
Explanation:
