August in Filadelfia is the sunniest month of the year. In August, the weather in Filadelfia is typically warm. Average daily high temperature in August is about 27 degrees above zero. On average, Filadelfia has 22 sunny, 8 partly cloudy, and 1 rainy day in August. The rains are usually light. August as well as June and July is considered the most comfortable time to visit Filadelfia.