In May, the weather in Bol'shaya Seya is typically warm. Average daily high temperature in May is about 16 degrees above zero. On average, Bol'shaya Seya has 14 rainy, 9 partly cloudy, 6 sunny, and 2 cloudy days in May. The rains are usually heavy. May as well as January, September, October, and December is considered the most uncomfortable time to visit Bol'shaya Seya.