August in Busan is the hottest month of the year. In August, the weather in Busan is typically hot. Average daily high temperature in August is about 29 degrees above zero. On average, Busan has 15 rainy, 7 sunny, 5 partly cloudy, and 4 cloudy days in August. The rains are usually heavy. August as well as January, February, March, and July is considered the most uncomfortable time to visit Busan.