Solid form of water that crystallizes in the atmosphere and falls to the Earth, covering about 23% of the Earth's surface either permanently or temporarily. Snowflakes are formed by crystals of ice that generally have a hexagonal pattern. Snow cover has a significant effect on climate and on plant, animal, and human life. By increasing the reflection of solar radiation and interfering with the conduction of heat from the ground, it induces a cold climate. The low heat conduction protects small plants from the effects of the lowest winter temperatures; on the other hand, late disappearance of snow in the spring delays the growth of plants.