September in Scranton is the sunniest month of the year. In September, the weather in Scranton is typically warm. Average daily high temperature in September is about 20 degrees above zero. On average, Scranton has 15 sunny, 8 rainy, 6 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as July is considered the most comfortable time to visit Scranton.