August in Ostromichi is the sunniest month of the year. In August, the weather in Ostromichi is typically warm. Average daily high temperature in August is about 23 degrees above zero. On average, Ostromichi has 12 sunny, 10 partly cloudy, 8 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 Ostromichi.