By heating the water the temperature of 0C to 4C, one can observe a decrease in its volume. In this temperature range, there is the phenomenon of anomalous thermal expansion of water.
The volume of water in the range of 0C to 4C decreases and 4C to 100C from growing. This anomalous behavior of water is associated with the fact that liquid water a temperature slightly above 0C, there are remnants of the loose structure of the ice. The temperature increase destroys this structure, allowing denser packing of the molecules, and thus the volume of water decreases.
