May in Velenje is the rainiest month of the year. In May, the weather in Velenje is typically warm. Average daily high temperature in May is about 17 degrees above zero. On average, Velenje has 22 rainy, 8 sunny, and 1 partly cloudy day in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Velenje.