August in Islandia is the sunniest month of the year. In August, the weather in Islandia is typically warm. Average daily high temperature in August is about 25 degrees above zero. On average, Islandia has 18 sunny, 8 partly cloudy, and 5 rainy days in August. The rains are usually moderate. August as well as July is considered the most comfortable time to visit Islandia.