July in Houston is the rainiest month of the year. In July, the weather in Houston is typically hot. Average daily high temperature in July is about 32 degrees above zero. On average, Houston has 15 rainy, 11 sunny, 3 partly cloudy, and 2 cloudy days in July. The rains are usually heavy. July as well as January, February, June, and August is considered the most uncomfortable time to visit Houston.