Believe it or not, hot water will freeze faster than cold water.
Anyone willing to see this phenomenon can perform this simple experiment at home: place two identical buckets – one filled with hot water and another filled with cold water – outside in a cold winter day and watch which one freezes first.
Well, you were warned : it is the one with hot water. The unexpected twist is explained by the following : when the water is initially hot, it gradually cools down and eventually reaches a “super cooled” condition which causes it to freeze entirely.
Under these same conditions the bucket with the cold water does not cool down evenly but rather a layer of ice forms at the surface of the water and it actually acts as insulation between the cold air and the cold water. This stops or at least slows down the process of freezing.
As a whole, hot water is less likely to reach a “super cool” overall temperature as it is less likely to contain gas bubbles which, in the case with cold water, are the basis for the formation of ice.