July in Biloxi is the hottest month of the year. In July, the weather in Biloxi is typically hot. Average daily high temperature in July is about 30 degrees above zero. On average, Biloxi has 15 rainy, 12 sunny, and 4 partly cloudy days in July. The rains are usually heavy. July as well as August is considered the most uncomfortable time to visit Biloxi.