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