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