May in Vestmannaeyjar is the sunniest month of the year. In May, the weather in Vestmannaeyjar is typically cold. Average daily high temperature in May is about 8 degrees above zero. On average, Vestmannaeyjar has 14 rainy, 8 sunny, 6 partly cloudy, and 3 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 Vestmannaeyjar.