The southern and western parts of Norway, fully exposed to Atlantic storm fronts, experience more precipitation and have milder winters than the eastern and far northern parts. Areas to the east of the coastal mountains are in a rain shadow, and have lower rain and snow totals than the west. The lowlands around Oslo have the warmest and sunniest summers, but also cold weather and snow in wintertime.

Because of Norway's high latitude, there are large seasonal variations in daylight. From late May to late July, the sun never completely descends beneath the horizon in areas north of the Arctic Circle (hence Norway's description as the "Land of the Midnight Sun"), and the rest of the country experiences up to 20 hours of daylight per day. Conversely, from late November to late January, the sun never rises above the horizon in the north, and daylight hours are very short in the rest of the country.  

The coastal climate of Norway is exceptionally mild compared with areas on similar latitude elsewhere in the world, with the Gulf Stream passing directly offshore the northern areas of the Atlantic coast. The temperature anomalies found in coastal locations are exceptional, with Røst and Værøy lacking a meteorological winter in spite of being north of the Arctic Circle. As a side-effect, the Scandinavian Mountains lock in continental winds from reaching the coastline, causing very cool summers throughout Atlantic Norway. Oslo has more of a continental climate, similar to the Swedish variety. The mountain ranges have subarctic and tundra climates. There is also very high rainfall at areas exposed to the Atlantic, such as Bergen. Oslo, in comparison, is very dry, being in a rain shadow.