The amount of darkness in Alaska varies depending on location within the state, although the darkest months are typically between November and late January. Some cities in Alaska see more light than others during the darkest months. North of the Arctic Circle, locations such as Barrow may receive up to 67 days of total darkness in the year, while others are plunged into complete darkness only during the height of the winter solstice, which occurs around December 21.
. In Alaskan towns and cities that lie North of the Arctic Circle, residents face nearly 70 days each year of total darkness because the sun sets around the middle of November and does not rise again until the end of January. In the summer months, however, Barrow receives nearly 80 days of perpetual sunlight, which is called the Midnight Sun. Generally, the Arctic Circle is considered the delineating point of the Midnight Sun. Locations south of the Arctic Circle have sunrises and sunsets each day while cities north of the Circle experience periods of time without sunrises or sunsets. Although Alaskan residents can look forward to long periods of sunlight in the summer, they are at a heightened risk of developing seasonal depression disorder from a prolonged lack of sunlight in the winter months. Seasonal depression can produce mild symptoms such as food cravings and lethargy as well as serious symptoms such as suicidal thoughts.