Great question, there are so many answers. Above the Arctic Circle, Alaska goes without light for about 3 months… Barrow, is the northern most US city, and the sun sets in mid-november and rises again in mid-february. On the contrary, in mid-May the sun rises and doesn’t set again until mid-August. In Anchorage, Alaska’s most populus city, the average day in the winter is about 6-8 hrs long, and in the summer is about 18-20 hrs long. In Fairbanks, about 125 miles south of the Arctic Circle they have about 2 months of mostly darkness, but it gets a little light between about noon and 2 pm. Again in the summer it is mostly light, but it gets a little darkish about midnight -2am. Great place to visit.