September in Pervomayskiy is the rainiest month of the year. In September, the weather in Pervomayskiy is typically warm. Average daily high temperature in September is about 10 degrees above zero. On average, Pervomayskiy has 19 rainy, 9 cloudy, 1 sunny, and 1 partly cloudy day in September. The rains are usually moderate. September as well as January, February, April, and October is considered the most uncomfortable time to visit Pervomayskiy.