May in Trento is the rainiest month of the year. In May, the weather in Trento is typically warm. Average daily high temperature in May is about 13 degrees above zero. On average, Trento has 20 rainy, 8 sunny, and 3 partly cloudy days in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Trento.