August in Vestmannaeyjar is the sunniest and the warmest month of the year. 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 17 rainy, 5 sunny, 5 partly cloudy, and 4 cloudy days in August. The rains are usually heavy. August as well as January, February, March, and April is considered the most uncomfortable time to visit Vestmannaeyjar.