Water on earth remains in a constant cycle. It moves from the ocean, seas, rivers, gets evaporated, goes into the atmosphere and again comes back to the earth in the form of rain, snow, hail etc. Snow is always formed in the cold clouds because their temperature is low, generally below freezing point. So because of low temperature small ice crystals are formed in the clouds. They increase in size when more water enters the cloud and the cloud become so large that the snow crystals remain suspended in the air. At this point we are not sure whether they fall as snow or air. It totally depends on the temperature of air through which it has to go. If the temperature is low it will fall as snow and again increase in size. They become heavy and big and finally break and fall as small ice crystals. Sometimes in mountain areas snow falls on the top of mountains and it rains lower in the valley because the air is warmer below.
Pure snow is made up of many small crystals from two to 200. These crystals are made around the tiny dust particles. So the ice crystals are the tiny dust particles in the form of ice. Scientists say that there are four types of crystal’s shape. One is long needle like ice crystals forming a spike; other is long hollow shaped crystals having six sides and appears like prism. One of them is thin crystal six sided plate and last one is intricate six sided pointed crystal. The shapes of ice crystals completely depend on the temperature of a particular place.
The largest snowflake ever measured has the diameter of 15 inches.