September in Bairnsdale is the windiest and the cloudiest month of the year. In September, the weather in Bairnsdale is typically warm. Average daily high temperature in September is about 17 degrees above zero. On average, Bairnsdale has 10 rainy, 10 partly cloudy, 7 sunny, and 3 cloudy days in September. The rains are usually moderate. September as well as June, July, August, and October is considered the most uncomfortable time to visit Bairnsdale.