From May to July, you can experience the Midnight Sun north of the Arctic Circle. The sun does not set below the horizon during this period. For the local population, this season provides an energy boost, a time when normal daylight in the middle of the night. Given fair weather, the sun is visible for a continuous 24 hours. The number of days per year with potential midnight sun increases the farther poleward one goes.
The Midnight Sun is visible at the Arctic Circle from June 12 until July 1. The further north you get the longer this period extends. At North Cape, known as the northernmost point of Continental Europe this period extends approximately from May 14 to July 29.
Many find it difficult to fall asleep during the night when the sun is shining. In general, visitors and newcomers are most affected. Some natives are also affected, but in general to a lesser degree. The effect of the midnight sun, that is, not experiencing night for long durations of time is said to cause hypomania.