August in Oita is the hottest month of the year. In August, the weather in Oita is typically hot. Average daily high temperature in August is about 30 degrees above zero. On average, Oita has 18 rainy, 6 sunny, 5 partly cloudy, and 2 cloudy days in August. The rains are usually heavy. August as well as January, February, March, and June is considered the most uncomfortable time to visit Oita.