Water freezes when it reaches certain
conditions of pressure and temperature. At the
temperature at the surface of the Earth, the
temperature is 0 degrees C (or 32 degrees F).
Water does not freeze unless its temperature
drops to that point - ever.
When you put water into a freezer, the cold
temperatures in the freezer lower the temperature
of the water until it reaches the freezing point,
at which point it freezes. The warmer the water is
to begin with, the farther it has to go before it