August in Melbourne is the rainiest, the cloudiest, and the hottest month of the year. In August, the weather in Melbourne is typically hot. Average daily high temperature in August is about 30 degrees above zero. On average, Melbourne has 20 rainy, 9 sunny, and 2 partly cloudy days in August. The rains are usually heavy. August as well as June, July, and September is considered the most uncomfortable time to visit Melbourne.