August in Sloviansk is the sunniest month of the year. In August, the weather in Sloviansk is typically hot. Average daily high temperature in August is about 28 degrees above zero. On average, Sloviansk has 23 sunny, 6 partly cloudy, 1 rainy, and 1 cloudy day in August. The rains are usually light. August as well as September is considered the most comfortable time to visit Sloviansk.