In September, the weather in Ust-Bolshereck is typically warm. Average daily high temperature in September is about 13 degrees above zero. On average, Ust-Bolshereck has 15 rainy, 6 cloudy, 5 partly cloudy, and 4 sunny days in September. The rains are usually heavy. September as well as May and October is considered the most uncomfortable time to visit Ust-Bolshereck.