August in Baton Rouge is the hottest month of the year. In August, the weather in Baton Rouge is typically hot. Average daily high temperature in August is about 33 degrees above zero. On average, Baton Rouge has 17 rainy, 7 sunny, 5 partly cloudy, and 2 cloudy days in August. The rains are usually heavy. August as well as June and July is considered the most uncomfortable time to visit Baton Rouge.