August in Clackamas is the warmest month of the year. In August, the weather in Clackamas is typically warm. Average daily high temperature in August is about 26 degrees above zero. On average, Clackamas has 27 sunny, 3 partly cloudy, and 1 rainy day in August. The rains are usually light. August as well as July is considered the most comfortable time to visit Clackamas.