August in Yuzhno-Sakhalinsk is the rainiest, the cloudiest, and the warmest month of the year. In August, the weather in Yuzhno-Sakhalinsk is typically warm. Average daily high temperature in August is about 20 degrees above zero. On average, Yuzhno-Sakhalinsk has 14 rainy, 8 partly cloudy, 7 cloudy, and 2 sunny days in August. The rains are usually heavy.