May in Savannakhet is the rainiest and the cloudiest month of the year. In May, the weather in Savannakhet is typically hot. Average daily high temperature in May is about 31 degrees above zero. On average, Savannakhet has 30 rainy and 1 sunny day in May. The rains are usually heavy. May as well as June, July, August, and September is considered the most uncomfortable time to visit Savannakhet.