August in Haeju is the warmest month of the year. In August, the weather in Haeju is typically warm. Average daily high temperature in August is about 27 degrees above zero. On average, Haeju has 15 rainy, 11 sunny, 3 partly cloudy, and 2 cloudy days in August. The rains are usually heavy. August as well as February, July, November, and December is considered the most uncomfortable time to visit Haeju.