September in Roanoke is the sunniest month of the year. In September, the weather in Roanoke is typically warm. Average daily high temperature in September is about 23 degrees above zero. On average, Roanoke has 16 sunny, 7 partly cloudy, 6 rainy, and 1 cloudy day in September. The rains are usually heavy. September as well as June, August, and October is considered the most comfortable time to visit Roanoke.