In May, the weather in Ratchaburi is typically hot. Average daily high temperature in May is about 34 degrees above zero. On average, Ratchaburi has 19 rainy, 9 cloudy, 2 partly cloudy, 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 Ratchaburi.