May in Adak Island is the cloudiest month of the year. In May, the weather in Adak Island is typically cold. Average daily high temperature in May is about 5 degrees above zero. On average, Adak Island has 23 rainy and 8 cloudy days in May. The rains are usually moderate. May as well as January, February, March, and April is considered the most uncomfortable time to visit Adak Island.