In August, the weather in Vestmannaeyjar is typically warm. Average daily high temperature in August is about 13 degrees above zero. On average, Vestmannaeyjar has 15 rainy, 7 sunny, 7 partly cloudy, and 2 cloudy days in August. The rains are usually moderate. August as well as January, February, March, and April is considered the most uncomfortable time to visit Vestmannaeyjar.