August in Katoomba is the sunniest month of the year. In August, the weather in Katoomba is typically warm. Average daily high temperature in August is about 13 degrees above zero. On average, Katoomba has 16 sunny, 7 rainy, 6 partly cloudy, and 2 cloudy days in August. The rains are usually light. August as well as January, February, March, and June is considered the most uncomfortable time to visit Katoomba.