In September, the weather in Posadnikov Ostrov is typically warm. Average daily high temperature in September is about 15 degrees above zero. On average, Posadnikov Ostrov has 13 rainy, 9 partly cloudy, 4 sunny, and 4 cloudy days in September. The rains are usually moderate. September as well as March, April, October, and November is considered the most uncomfortable time to visit Posadnikov Ostrov.