September in Ballarat is the windiest month of the year. In September, the weather in Ballarat is typically warm. Average daily high temperature in September is about 13 degrees above zero. On average, Ballarat has 15 rainy, 6 partly cloudy, 5 sunny, and 4 cloudy days in September. The rains are usually light. September as well as July and August is considered the most uncomfortable time to visit Ballarat.