May in Manchester is the sunniest month of the year. In May, the weather in Manchester is typically warm. Average daily high temperature in May is about 13 degrees above zero. On average, Manchester has 20 rainy, 6 sunny, 3 cloudy, and 2 partly 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 Manchester.