May in Trebon is the rainiest month of the year. In May, the weather in Trebon is typically warm. Average daily high temperature in May is about 16 degrees above zero. On average, Trebon has 14 rainy, 10 sunny, and 7 partly cloudy days in May. The rains are usually moderate. May as well as January, February, March, and November is considered the most uncomfortable time to visit Trebon.