Snow is the most common form of solid precipitation. Snow consists of ice crystals which can come in all shapes and sizes. Temperatures below 0° C are not sufficient to form snow. Crystallization nucleuses which are very fine particles of dust must be able to attach themselves which necessitates temperatures below -12° C, because
water remains fluid up to a temperature as low as -40C°. The first snow crystals are smaller than 0.1 mm but grow in size due to gravity as they approach the earth. The crystals come in all shapes and sizes but as a result of the structure of the molecules are always hexagonal. Depending on the temperature, the humidity and the
movement of the air, new crystal variations continue.

Snow flakes consist of a large number of individual crystals. Due to their large surface and low weight they fall to the ground slowly. They retain their characteristic white color because light is reflected and dispersed on the air and the bordering surfaces of the ice crystals which are actually diaphanous. Because the way in which the ice crystals correlate with each other the reflection itself is diffuse making the snow appear to be white.

Snow is very welcome in winter sport areas, less welcome when it comes to traffic. When streets are covered with snow they can become very slippery and cause a large number of accidents. If the snow is cleared away early enough the streets can dry in sunny weather which prevents traffic from congesting.

Winter sport depends on snow and utilizes the conductivity of snow crystals for various types of sports, which includes skiing in its many variations, sledding and snowboarding, to name just a few. Artificial snow is added when there is not enough snow. In doing so, water is artificially atomized and dispersed with the help of snow canons so that the slopes can be used again.

Powder snow is particularly popular. It is dry and does not stick, even if pressed, so that the conductivity continues to be good. What is less popular for winter sports is wet and sticky snow which sticks when pressed and requires a second cover or the waxing of the skies if it is to be used. Children love sticky snow because it can be used to build snow men and igloos. Wet snow is hardly suitable for winter sports.

Water seeps out when it is compressed. A mixture of snow and water is referred to as slush and when it rains at the same time when it snows it is referred to as snow rain.