July in Dickinson is the sunniest and the warmest month of the year. In July, the weather in Dickinson is typically warm. Average daily high temperature in July is about 27 degrees above zero. On average, Dickinson has 23 sunny, 4 rainy, and 4 partly cloudy days in July. The rains are usually moderate. July as well as August and September is considered the most comfortable time to visit Dickinson.