September in McGrath is the windiest month of the year. In September, the weather in McGrath is typically warm. Average daily high temperature in September is about 11 degrees above zero. On average, McGrath has 13 rainy, 9 cloudy, 4 sunny, and 4 partly cloudy days in September. The rains are usually moderate. September as well as January, February, August, and October is considered the most uncomfortable time to visit McGrath.