The climate of the Russian Federation formed under the influence of several determining factors. The enormous size of the country and the remoteness of many areas from the sea result in the dominance of the humid continental and subarctic climate, which is prevalent in European and Asian Russia except for the tundra and the extreme southeast. Mountains in the south obstructing the flow of warm air masses from the Indian Ocean and the plain of the west and north makes the country open to Arctic and Atlantic influences.
Throughout much of the territory there are only two distinct seasons — winter and summer; spring and autumn are usually brief periods of change between extremely low temperatures and extremely high. The coldest month is January (on the shores of the sea—February), the warmest usually is July. Great ranges of temperature are typical. In winter, temperatures get colder both from south to north and from west to east. Summers can be quite hot and humid, even in Siberia. A small part of Black Sea coast around Sochi has a subtropical climate. The continental interiors are the driest areas.