May in Susa Valley is the rainiest and the cloudiest month of the year. In May, the weather in Susa Valley is typically warm. Average daily high temperature in May is about 11 degrees above zero. On average, Susa Valley has 24 rainy, 5 sunny, and 2 partly cloudy days in May. The rains are usually heavy. May as well as March, April, June, and November is considered the most uncomfortable time to visit Susa Valley.