WINTER
SPRING
You can also experince the land of the midnight sun June-July where you can sit up until the early hours and still feel like it is the middle of day...
SUMMER
Late June to early August is when the weather is warmest and the days are long and bright. Temperatures in July and August can reach 25°C - 30°C. At the same time there is hardly any humidity in the air so you can get some relaly beautiful weather. On the flip side the summer weather can be wet and changeable especially in Fjord Norway. If you want to experience the Land of the Midnight Sun you will have to travel to the northern part of the country in June - July.
AUTUMN
During autumn the land areas lose more heat than the sea, and eventually the coastal areas have the highest temperatures. In September the outer part of the Oslofjord usually has the highest mean temperatures. Later in the autumn, the warmest areas are usually found on the coast of Rogaland and Hordaland.
So as you can see there really isn't a 'best' time to go as each season in Norway holds something a little bit special for you. With cruise lines such as Hurtigruten who specialise in Norway and Cruise and Maritime there are lots of choices and itineraries to choose from so if you are thinking about a cruise to Norway then hopefully this has helped in deciding for you when would be the best time for you to go.