Beware of the midnight sun
You've certainly heard of Norway's midnight sun, but depending on the time of year you visit, it's not always what you imagine. Polar evenings are a phenomenon that occurs in Northern Norway throughout the winter. As a result, the sun never rises over the horizon, and the day is effectively black. The opposite is true in the summer. The sun never entirely sets.
Northern Norway experiences polar nights throughout the winter, when the sun never rises over the horizon and there are 24 hours of darkness. Summer, on the other hand, is completely different; the sun never sets.
You've probably heard of the Midnight Sun. Unlike popular belief, the midnight sun is not a different sun...it is simply the same sun as the rest of the year, but it does not set, resulting in 24 hours of sunshine.