No, it is not always dark in Alaska and the length of day depends a lot on the season and different regions of the state. For example in summer season, the days are quite long and warm during May and June with the longest day coming on June 21st. During summers, in the region of Ketchikan, the day can be as long as 18 hours, anchorage gets 19 and a half hours of sunlight, fair banks gets sunlight of 21 hours and Barrow gets 24 hours of sunlight. Even in winter season, total darkness does not come to all the parts of Alaska. The parts above the Arctic Circle go into complete darkness. In rest of the areas, there is sunlight form some time of the day but it is very pale.