July in Lake Ozark is the hottest month of the year. In July, the weather in Lake Ozark is typically hot. Average daily high temperature in July is about 31 degrees above zero. On average, Lake Ozark has 14 sunny, 10 rainy, and 7 partly cloudy days in July. The rains are usually heavy. July as well as January, February, March, and May is considered the most uncomfortable time to visit Lake Ozark.