寒带分为南寒带，北寒带。南寒带是南极圈（南纬66.5度）以内的区域，北寒带是北极圈（北纬66.5度）以内区域。

在南寒带，南极洲大陆完全被冰覆盖，四周受到极地东风带的强劲吹拂。南寒带气候异常恶劣，保持着地球上的最低温记录和最强风记录。在南极洲植物稀少，仅有苔藓、藻类、地衣和几种显花植物，而且大都生长在南极圈以外的南极半岛。主要集中在南大洋。

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 10 °C (50 °F). 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.