July in Penticton is the sunniest and the warmest month of the year. In July, the weather in Penticton is typically warm. Average daily high temperature in July is about 22 degrees above zero. On average, Penticton has 25 sunny, 5 partly cloudy, and 1 rainy day in July. The rains are usually light. July as well as August is considered the most comfortable time to visit Penticton.