July in Penzance is the warmest month of the year. In July, the weather in Penzance is typically warm. Average daily high temperature in July is about 17 degrees above zero. On average, Penzance has 19 rainy, 8 sunny, 3 partly cloudy, and 1 cloudy day in July. The rains are usually moderate. July as well as January, February, March, and November is considered the most uncomfortable time to visit Penzance.