July in Gastonia is the rainiest, the cloudiest, and the hottest month of the year. In July, the weather in Gastonia is typically hot. Average daily high temperature in July is about 30 degrees above zero. On average, Gastonia has 16 rainy, 8 partly cloudy, 5 sunny, 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 Gastonia.