In May, the weather in Ratchaburi is typically hot. Average daily high temperature in May is about 35 degrees above zero. On average, Ratchaburi has 23 rainy, 3 sunny, 3 partly cloudy, and 2 cloudy days in May. The rains are usually heavy. May as well as April, June, July, and August is considered the most uncomfortable time to visit Ratchaburi.