September in Olyokminsk is the rainiest month of the year. In September, the weather in Olyokminsk is typically cold. Average daily high temperature in September is about 8 degrees above zero. On average, Olyokminsk has 14 rainy, 12 cloudy, and 4 sunny days in September. The rains are usually light. September as well as January, February, March, and May is considered the most uncomfortable time to visit Olyokminsk.