September in Angleton is the rainiest month of the year. In September, the weather in Angleton is typically hot. Average daily high temperature in September is about 29 degrees above zero. On average, Angleton has 15 sunny, 14 rainy, and 1 partly cloudy day in September. The rains are usually heavy. September as well as January, June, July, and August is considered the most uncomfortable time to visit Angleton.