Polar climates are those in which the temperature of
the warmest season always remains below 10 °C. In this climatic
class are found the sub polar climate and the perennial ice climate.
The first one, with very rigorous winters, cool summers and scarce
precipitations during the whole year, produces vegetation devoid of
trees which is essentially constituted by moss and lichens (tundra).
The perennial ice climate has temperatures which are constantly
below 0 °C and practically no vegetation. In the area where this
climate is present, Antarctica, at the meteorological station of
Vostok, has been registered the lowest measured temperature ever
recorded on the planet: -91,5 °C.