September in Pattaya is the rainiest and the cloudiest month of the year. In September, the weather in Pattaya is typically hot. Average daily high temperature in September is about 29 degrees above zero. On average, Pattaya has 23 rainy, 5 cloudy, and 2 partly cloudy days in September. The rains are usually heavy. September as well as May, June, July, and August is considered the most uncomfortable time to visit Pattaya.