September in Ostrov Bol'shoy Oleny is the rainiest month of the year. In September, the weather in Ostrov Bol'shoy Oleny is typically cold. Average daily high temperature in September is about 9 degrees above zero. On average, Ostrov Bol'shoy Oleny has 17 rainy, 5 cloudy, 5 partly cloudy, and 3 sunny days in September. The rains are usually heavy. September as well as May, June, July, and August is considered the most uncomfortable time to visit Ostrov Bol'shoy Oleny.