May in Tulsa is the rainiest month of the year. In May, the weather in Tulsa is typically warm. Average daily high temperature in May is about 26 degrees above zero. On average, Tulsa has 13 rainy, 12 sunny, and 6 partly 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 Tulsa.