Cartographically speaking, the polar regions are those north of latitude 66.5° north and south of latitude 66.5° south. These are the lands of the midnight sun, where the nights are short or nonexistent during the summer and the days likewise during the winter. However, because of terrain, winds, and ocean currents, polar climatic types may stray outside these geographical limits, or may not quite reach them.
Under the Köppen-Tregartha system, the type of climate found at and near the poles is designated E. Needless to say, these are cold and harsh, and most of what little precipitation falls does so as snow.
By Dave Bryant, copyright 2002