May in Kansas City is the rainiest and the cloudiest month of the year. In May, the weather in Kansas City is typically warm. Average daily high temperature in May is about 24 degrees above zero. On average, Kansas City has 14 rainy, 8 sunny, 7 partly cloudy, and 2 cloudy days in May. The rains are usually heavy. May as well as January, February, March, and June is considered the most uncomfortable time to visit Kansas City.