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