May in Kyustendil is the rainiest month of the year. In May, the weather in Kyustendil is typically warm. Average daily high temperature in May is about 17 degrees above zero. On average, Kyustendil has 17 rainy, 11 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 Kyustendil.