The main factor influencing Finland's climate is the country's geographical position between the 60th and 70th northern parallels in the Eurasian continent's coastal zone. In the Köppen climate classification, the whole of Finland lies in the boreal zone, characterized by warm summers and freezing winters. Within the country, the temperateness varies considerably between the southern coastal regions and the extreme north, showing characteristics of both a maritime and a continental climate. Finland is near enough to the Atlantic Ocean to be continuously warmed by the Gulf Stream. The Gulf Stream combines with the moderating effects of the Baltic Sea and numerous inland lakes to explain the unusually warm climate compared with other regions that share the same latitude, such as Alaska, Siberia, and southern Greenland.