The
polar climate regions are characterized by a lack of warm
summers. Every month in a polar climate has an average temperature of less than . Regions with polar climate cover more than 20% of the Earth. The sun shines for long hours in the summer, and for many fewer hours in the
winter. A polar climate results in treeless
tundra,
glaciers, or a permanent or semi-permanent layer of
ice. It has cool summers and very cold winters.