August in Ust-Usa is the rainiest month of the year. In August, the weather in Ust-Usa is typically warm. Average daily high temperature in August is about 15 degrees above zero. On average, Ust-Usa has 14 rainy, 9 cloudy, 6 partly cloudy, and 2 sunny days in August. The rains are usually moderate. August as well as January, February, May, and September is considered the most uncomfortable time to visit Ust-Usa.