September in Chachoengsao is the rainiest month of the year. In September, the weather in Chachoengsao is typically hot. Average daily high temperature in September is about 32 degrees above zero. On average, Chachoengsao has 28 rainy, 1 cloudy, and 1 partly cloudy day in September. The rains are usually heavy. September as well as April, May, June, and July is considered the most uncomfortable time to visit Chachoengsao.