` The longest night occurs on December 21st in the Northern Hemisphere and June 21st in the Southern Hemisphere. All land higher than 66° latitude experiences 24 hours of darkness during one of these days. Reverse the days and they have 24 hour daylight, June 21st for the north, December 21st for the south. So nowhere is there 24 hours darkness all year long.
Here are the countries that have the most land experiencing 24 hour darkness during the year :