September in Laramie is the sunniest month of the year. In September, the weather in Laramie is typically warm. Average daily high temperature in September is about 21 degrees above zero. On average, Laramie has 19 sunny, 7 rainy, 3 partly cloudy, and 1 cloudy day in September. The rains are usually light. September as well as June and August is considered the most comfortable time to visit Laramie.