Because of the North Atlantic Drift, Norway has a mild climate for a country so far north. With the great latitudinal range, the north is considerably cooler than the south, while the interior is cooler than the west coast, influenced by prevailing westerly winds and the Gulf Stream. Oslo's average yearly temperature ranges from a about 5° C (41° F ) in January to 28° C (82° F ) in July. The annual range of coastal temperatures is much less than that of the continental interior. The eastern valleys have less than 30 cm (12 in) of rain yearly, whereas at Haukeland in Masfjord the average rainfall is 330 cm (130 in).
Norway is the land of the midnight sun in the North Cape area, with 24-hr daylight from the middle of May to the end of July, during which the sun does not set. Conversely, there are long winter nights from the end of November to the end of January, during which the sun does not rise above the horizon and the northern lights, or aurora borealis, can be seen.