Saturday, September 19, will bring a large gap between morning and daytime temperatures across much of Korea. The forecast calls for lows around 15 degrees Celsius and highs reaching 30 degrees in some areas, with a day-night range of roughly 10 to 15 degrees outside the east coast. Rain is concentrated along parts of the Gangwon and Gyeongsang east coast and on Jeju.
Expected rainfall for September 18 to 19 is 5 to 10 millimeters in the Gangwon mountains and 5 to 20 millimeters on Jeju, while several east-coast areas are forecast to receive less than 5 millimeters. Much of the rest of the country should be mostly clear. The practical weather story is the contrast: cool starts, warm afternoons and localized rain rather than a nationwide wet day.