July in South Dayton is the warmest month of the year. In July, the weather in South Dayton is typically warm. Average daily high temperature in July is about 24 degrees above zero. On average, South Dayton has 16 sunny, 8 rainy, and 7 partly cloudy days in July. The rains are usually moderate. July as well as August is considered the most comfortable time to visit South Dayton.