September in Breckenridge is the sunniest month of the year. In September, the weather in Breckenridge is typically warm. Average daily high temperature in September is about 10 degrees above zero. On average, Breckenridge has 14 rainy, 14 sunny, and 2 partly cloudy days in September. The rains are usually heavy. September as well as May, July, and August is considered the most uncomfortable time to visit Breckenridge.