May in Sloviansk is the rainiest month of the year. In May, the weather in Sloviansk is typically warm. Average daily high temperature in May is about 20 degrees above zero. On average, Sloviansk has 16 rainy, 12 sunny, and 3 partly cloudy days in May. The rains are usually heavy. May as well as March, November, and December is considered the most uncomfortable time to visit Sloviansk.