It's going to be a bit cold in Oslo on Friday. Normal January temperatures here are closer to -1ºC. In July, we get +17ºC on average.
Discussion
Some places in the north will see -40ºC but we're talking the Arctic parts, and inland areas, where temperatures are always extreme.
Once upon a time I rented a car in Oslo, drove it through Drevsjø, and the coolant in the radiator literally froze solid while I was driving down the road. Cold doesn’t start to describe the conditions outside on that day. A tow and a warm cup of tea had me on my way in no time. The technician said, did you expect that it wouldn’t freeze? Yes, I suppose I did.