September in Coonamble is the sunniest month of the year. In September, the weather in Coonamble is typically warm. Average daily high temperature in September is about 23 degrees above zero. On average, Coonamble has 21 sunny, 4 rainy, 4 partly cloudy, and 1 cloudy day in September. The rains are usually moderate. September as well as April and May is considered the most comfortable time to visit Coonamble.