The climate of Norway is much milder than that of most other regions as far north, especially along the country's west coast. Snow that falls along the coast melts often immediately. The warm North Atlantic Current of the Gulf Stream keeps nearly all the seaports ice-free, even in the northern regions. During winter, Norway's inland regions are colder than the coast because mountains block the warm west winds from the sea.
Snow covers the ground at least three months a year. During the summer months, when the sea is cooler than the land, the stuation is different; then the west winds cool the coast more than the inland so the warmest summers are in the inland valleys of the southeast. Average temperatures vary between -10°C in January in Spitzbergen and +16°C in July in Oslo.
Precipitation in norway varies between 500 and 3000 mmm per year. the most rain falls along the coastal areas, less rain falls inland and in the eastern parts of Norway.
Northern Norway lies in the Land of the Midnight Sun and knows continuous daylight during part of the summer. The number of days of continuous daylight increases as one goes farther north. In northernmost Norway, the sun stays above the horizon for about 2,5 months. Southern Norway never has continuous daylight, though it averages 19 hours of daylight a day in midsummer. In winter, Norway has similar periods of continuous darkness. In the northernmost areas of the country the sun never rises above the horizon for about 2 months. Southern Norway has some daylight each day, though it receives only about 6 hours of daylight a day in midwinter. The winter night sky often becomes enriched with brilliant displays of aurora borealis or northern lights.