August in Waxahachie is the hottest month of the year. In August, the weather in Waxahachie is typically hot. Average daily high temperature in August is about 34 degrees above zero. On average, Waxahachie has 20 sunny, 6 rainy, and 5 partly cloudy days in August. The rains are usually moderate. August as well as January and December is considered the most uncomfortable time to visit Waxahachie.