August in Adak Island is the warmest month of the year. In August, the weather in Adak Island is typically warm. Average daily high temperature in August is about 11 degrees above zero. On average, Adak Island has 25 rainy, 5 cloudy, and 1 sunny day in August. The rains are usually moderate. August as well as January, February, March, and April is considered the most uncomfortable time to visit Adak Island.