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