Because Barrow is located above the Arctic Circle, there are times of the year during which the sun never sets, and other times when it never rises above the horizon. Instead of dipping below the horizon every day, during the summer the sun circles around the sky above the horizon. The sun sets on November 18 or 19, and remains below the horizon for about 65 days — that is, until the end of January. In the middle of this polar night (December 21-22), the sky is completely dark all the time, except for about 3 hours of twilight.