Finland is characterized by warm summers and freezing winters. Within the country, the temperateness varies considerably between the southern coastal regions and the extreme north. Winters in southern Finland (when mean daily temperature remains below 0 °C or 32 °F) are usually about 100 days long, and in the inland the snow typically covers the land from about late November to April, and on the coastal areas such as Helsinki, snow often covers the land from late December to late March. Climatic summers (when mean daily temperature remains above 10 °C or 50 °F) in southern Finland last from about late May to mid-September, and in the inland, the warmest days of July can reach over 35 °C (95 °F).

In northern Finland, particularly in Lapland, the winters are long and cold, while the summers are relatively warm but short. The most severe winter days in Lapland can see the temperature fall down to −45 °C (−49 °F). The winter of the north lasts for about 200 days with permanent snow cover from about mid-October to early May. Summers in the north are quite short, only two to three months, but can still see maximum daily temperatures above 25 °C (77 °F) during heat waves. A quarter of Finland’s territory lies within the Arctic Circle and the midnight sun can be experienced for more days the farther north one travels. At Finland’s northernmost point, the sun does not set for 73 consecutive days during summer, and does not rise at all for 51 days during winter.