Weather in Norway is much warmer than what might be expected from its location geographically. It is due to the warmth of the Gulf Stream that most of the land of Norway falls within the zone of the temperate climate.
Weather in Norway varies significantly from the coastal to the inland areas. The regions near the coast have a climate that has mild winters. The summer months are considerably cooler. The interior parts of Norway have a continental climate along with winters that are much cooler. But the summers are quite warmer. Oslo has this particular kind of climate.
Norway is a Scandinavian country and it has a climate that fluctuates considerably from year to year. This happens especially in most of the northern parts. The same weather persists at the edge of the global temperate zone.
There is a very interesting phenomenon in the weather in Norway and this is prevalent in some other parts of Scandinavia as well. This is the seasonal change that occurs in the length of day and night. In the middle of the winter season daylight lasts only 5 to 6 hours in southern Norway and darkness prevails in the north. These totally dark days and nights are a phenomenon that is essentially a Scandinavian feature and it is called the Polar Nights.
During summer daylight rules and there is no night. This is the same as far as Trondheim. The name for this phenomenon is the Midnight Sun.
Norway experiences warmer temperatures and this is due to the Gulf Stream and the Westerlies. There is more along the coast. The mainland of Norway experiences four distinct seasons. Winters are cold and precipitation is less as one travels further inland. The northernmost part of Norway has a maritime Sub arctic climate and Svalbard has an Arctic tundra climate.