September in Zheleznogorsk is the cloudiest month of the year. In September, the weather in Zheleznogorsk is typically warm. Average daily high temperature in September is about 13 degrees above zero. On average, Zheleznogorsk has 13 rainy, 8 cloudy, 6 partly cloudy, and 3 sunny days in September. The rains are usually moderate. September as well as January, February, October, and December is considered the most uncomfortable time to visit Zheleznogorsk.