August in Chillan is the rainiest and the cloudiest month of the year. In August, the weather in Chillan is typically warm. Average daily high temperature in August is about 14 degrees above zero. On average, Chillan has 15 rainy, 9 sunny, 6 partly cloudy, and 1 cloudy day in August. The rains are usually heavy. August as well as June and July is considered the most uncomfortable time to visit Chillan.