Compared to the high latitude, Norway has a mild climate because of the influence of the warm Gulf Stream.
Visiting Norway, you will find that May through September is the busiest months. You can also expect the warmest weather, the most extended daylight hours, and the best availability of outdoor activities.
In the summer, the average temperature in Norway ranges between 13°-18°C (57° to 65°F). In July and August, the temperatures can reach 25°C - 30°C. The warmest and most stable weather usually occurs on the eastern side of the southern mountains, including the south coast between Mandal and Oslo. Summer temperatures are pleasant even further north – sometimes reaching as high as 25°C or more.
The best time to visit Norway is from mid-May until late July. Here the Midnight Sun phenomenon is at its peak. Above the Arctic Circle, the sun shines night and day from mid-May until late July. To experience the Midnight Sun's best views, you must travel to the country's northern part and visit towns as Tromsø, the Lofoten Islands, North Cape and Narvik.
Summer weather can be changeable, especially in Fjord Norway, Trøndelag and Northern Norway. The west coast receives the most rain, but the area farther east is drier. The Atlantic Gulf Stream keeps the western fjord area and the coast up into the Arctic North much warmer than you might expect.
The sea temperature can reach 18°C (64°F) or higher on the south coast, where swimming is popular. Surprisingly, the water is often calm, as most of the inhabited places in Norway are sheltered from the prevailing wind by mountains and forests.
Be sure to have waterproof clothing. If you should be unlucky with the weather, remember a wise Norwegian saying, "There is no such thing as bad weather, only bad clothing.
See also: What to pack for visiting Norway
In winter, much of Norway is transformed into a snow-clad paradise from November to April. It is an excellent time for holidays in Norway's northern regions if you wish to discover the Northern Lights. These months offer the best opportunities for viewing the Northern Lights and ideal snow conditions for dog-sledging, snowmobiling, skiing and other winter sports.
What about just sitting by the fire in a warm and cosy log cabin is a pleasure for some, as is the friendly, relaxed atmosphere of the hotel bar. In the northern part of the country, you will find shallow temperatures in winter. Temperatures can reach below -40°C in the inner areas of Finnmark.
Average temperatures in Norway from January to December: