May in Sheboygan is the rainiest month of the year. In May, the weather in Sheboygan is typically warm. Average daily high temperature in May is about 16 degrees above zero. On average, Sheboygan has 11 rainy, 9 partly cloudy, 7 sunny, and 4 cloudy days in May. The rains are usually heavy. May as well as February, March, April, and October is considered the most uncomfortable time to visit Sheboygan.