Learn and have fun
There is no shortage of exciting museums to visit in Norway, whatever your children’s interests and age.
Norwegian explorers and the vessels they used on their fabulous adventures always captivate, whether it is Thor Heyerdahl's Kon-Tiki raft; the polar ship Fram, made famous by Nansen and Amundsen; or the magnificent Viking longships (all in Oslo). See more about the Kon-Tiki Museum, the Fram Museum and the Viking Ship Museum.
Elsewhere your family can learn about Norway's oil industry through interactive activities at the Norwegian Petroleum Museum in Stavanger, and even take part in a drill exercise, just as they would on an off-shore platform.
Or check out the brand new Rockheim ("the Home of Rock") in Trondheim, where visitors can listen to Norwegian rock and pop music, but also mix their own hip-hop track, and experience what it feels like to perform in front of a packed audience.
Make new friends
Kids love animals, so a day spent making new furry (or slimy) friends is bound to be a winner. Many farms open their doors during school holidays, allowing children to watch, feed and pet the animals. Ask at your local tourist office for details of farms near you.
Other good indoor options include Bergen Aquarium, which celebrated its 50th birthday in 2010. Try to get there for penguins' feeding time (11 am or 5 pm) – this never fails to enchant children. The aquarium is the largest in Norway, and it is very popular. So are Atlanterhavsparken in Ålesund, one of the largest saltwater-aquariums in northern Europe, and Polaria in Tromsø, the only place in the world where bearded seals can be seen in captivity.
The Oslo Reptile Park is also worth a visit – it features over 100 reptiles and amphibians, including boa constrictors, pythons, grass snakes, lizards, chameleons and iguanas, to name but a few.
Nurture budding artists
Looking for something a bit more "arty"? No reason to scream (although you could check out that icon of Norwegian expressionism too!) - there are plenty of child-friendly art galleries to choose from.
The Munch Museum and the National Gallery in Oslo are two of the most famous, but Bergen and Lillehammer also boast extensive collections, and there are art galleries in pretty much all the big towns in Norway. Many of them offer activities for children, ranging from colouring sheets to workshops and guided tours for families.
The most popular with kids, however, has to be the International Children's Art Museum (Barnekunst Museum) in Oslo, which has a unique collection of drawings, paintings and sculptures by children from around the world. Inspiring stuff!
Get active
Staying indoors doesn't have to mean the kids can't burn off excess energy either. A trip to the local swimming pool will keep them entertained for a couple of hours without breaking the bank.
Or your family could spend the day at one of many indoor water-parks, so that mum and dad can chill out in the jacuzzi while the kids splash out in the wave pool or down the water slides. Popular venues include Atlanterhavsbadet in Kristiansund, Grottebadet in Harstad and Drammensbadet in Drammen, 40km (25 miles) east of Oslo.
Want a more typically Nordic option? Go for a spin at the local ice-rink! Most are open to the public from early autumn to late spring, but call beforehand to check whether skate hire is available, as this is not the case everywhere.
Indoor climbing, bowling, go-karting and paintballing are other options for teenagers, while indoor playgrounds such as Child Planet in Oslo, which offers slides, climbing frames, a plastic ball pit and more, will appeal to younger children.
Brave the elements
And of course just because it's raining doesn't mean you can't venture outside. "There is no bad weather, only bad clothing", goes an age-old Norwegian saying. Do as the locals do – get the rubber-boots out, zip up those rain-jackets, and just go for that walk in the woods anyway. After all, kids love splashing in puddles, right?
Stop by the local café on the way back for a hot drink, a pastry and a log fire to warm up. It is worth noting that many hostels, campsites and cabins in rural areas have drying machines and even put shoe dryers at the disposal of their guests. So you needn't be wet for too long.
Have fun on your trip to Norway - whatever the weather!