The midnight sun is a phenomenon occurring in latitudes north of the Arctic Circle and south of the Antarctic Circle where the sun is visible at the local midnight. Given fair weather conditions, the sun is visible for a continuous 24 hours. Since there are no permanent human settlements south of the Antarctic Circle, the countries and territories whose population experiences it are limited to the ones crossed by the Arctic Circle, i.e.
The sky must be clear and there must be unobstructed visibility northwards in order to see the Midnight Sun. A summer night on the fjord or in the mountains is an experience not to be missed, you can go fishing in the fjord, which contains splendid variation of fish, or you can take a walk in the wilderness surrounding.
The opposite phenomenon, polar night, is observed in winter when the sun is sufficiently below the horizon, so that there is insufficient sunlight or no light at all. (A lingering dusk may occur, if the sun is only 12 degrees or less below the horizon.)
Since the Earth´s axis is tilted with respect to the ecliptic by approximately 23 degrees 27 minutes (commonly rounded to 23 degrees and a half), the sun does not set at high latitudes in (local) summer. The duration of the midnight sun increases from one day during the summer solstice at the polar circle to approximately six months at the poles. At extreme latitudes, it is usually referred to as polar day. The length of the time when the sun is above the horizon varies from 20 hours at the Arctic Circle and Antarctic Circle to 186 days at the poles.
At the poles themselves, the sun only rises once and sets once, each year. During the six months when the sun is above the horizon at the poles, the sun spends the days constantly moving around the horizon, reaching its highest circuit of the sky at the summer solstice.
MIDNIGHT SUN EFFECT ON PEOPLE
Many find it difficult to fall asleep during the night when the sun is shining. In general, visitors and newcomers are most affected; they are easily spotted in residential areas by the aluminum foil glued onto their bedroom windows to obtain darkness inside. Some natives are also affected, but in general to a lesser degree, and some say it´s therapy to the SOUL.
Summer Midnight at Latitude 60.4
Due to refraction, the midnight sun may be experienced at latitudes slightly below the polar circle, though not exceeding one degree (depending on local conditions).
SEE VIDEOs of THE MIDNIGHT SUN.
North Cape is normally denoted as the northernmost point in Europe, there are 76 days (from 14 May to 30 July) of proper midnight sun and an additional few days with partial sun before and after.
In Svalbard the northernmost inhabited region of Europe, there is no sunset from approximately April 19th to August 23rd. The extreme sites are the poles where the sun can be visible for a continuous half year.