September in Usole-Sibirskoe is the rainiest and the sunniest month of the year. In September, the weather in Usole-Sibirskoe is typically warm. Average daily high temperature in September is about 13 degrees above zero. On average, Usole-Sibirskoe has 13 sunny, 9 partly cloudy, and 8 rainy days in September. The rains are usually light.