The weight of a certain amount of water. It is usually expressed in kilograms per cubic metre. The temperature of the water is the greatest influence on the weight of the water per its unit volume. Pure water has a density of less than 1 g/cm3 and a standard table will provide a set of values that categorize the density of liquid water. It should be mentioned that water is capable of being cooled to a great degree and still remains as a liquid. The density of water reaches its maximum limit at four degrees celsius, which means it is even more dense than ice, which is why ice tends to flat on water.