August in Colac is the rainiest month of the year. In August, the weather in Colac is typically warm. Average daily high temperature in August is about 12 degrees above zero. On average, Colac has 27 rainy, 3 sunny, and 1 cloudy day in August. The rains are usually moderate. August as well as May, June, July, and September is considered the most uncomfortable time to visit Colac.