September in Churchill Falls is the cloudiest month of the year. In September, the weather in Churchill Falls is typically warm. Average daily high temperature in September is about 11 degrees above zero. On average, Churchill Falls has 16 rainy, 8 partly cloudy, 5 cloudy, and 1 sunny day in September. The rains are usually heavy. September as well as January, February, March, and May is considered the most uncomfortable time to visit Churchill Falls.