July in Plymouth is the windiest month of the year. In July, the weather in Plymouth is typically warm. Average daily high temperature in July is about 27 degrees above zero. On average, Plymouth has 20 rainy, 5 sunny, 5 partly cloudy, and 1 cloudy day in July. The rains are usually moderate. July as well as August, September, October, and November is considered the most uncomfortable time to visit Plymouth.