On Monday the 20th, rain is expected in most parts of the country from morning through afternoon. In the afternoon, fine dust levels in the greater Seoul area and elsewhere will worsen due to yellow dust.
The Korea Meteorological Administration said on the 19th that "until late afternoon tomorrow, Jeju Island, and from morning through afternoon tomorrow, the central region except the east coast of Gangwon, as well as North Jeolla in the Jeolla region, the northern Jeolla region in South Jeolla, and inland areas of North and South Gyeongsang will see rain."
Before dawn, parts of the Chungcheong region and eastern North Jeolla will see less than 0.1 mm of rain. Expected precipitation is less than 5 mm for Seoul, Incheon, and Gyeonggi, and the five West Sea islands; less than 5 mm for inland and mountainous Gangwon; less than 5 mm for Daejeon, Sejong, and South and North Chungcheong; less than 5 mm for Gwangju, northern South Jeolla, and North Jeolla; less than 5 mm for Daegu, inland and northeastern mountainous North Gyeongsang, and inland South Gyeongsang; and 5–20 mm for Jeju Island (on the 19th–20th).
Due to a trough passing to the north and a low-pressure system over the waters south of Jeju Island, skies across the country will turn cloudy from dawn but clear from late afternoon.
Morning lows are forecast at 10–15 C, with afternoon highs at 16–25 C. Morning temperatures in major areas will be Seoul 14 C, Incheon 12 C, Suwon 13 C, Chuncheon 12 C, Gangneung 14 C, Cheongju 14 C, Daejeon 14 C, Jeonju 14 C, Gwangju 14 C, Daegu 14 C, Busan 15 C, and Jeju 15 C. Afternoon highs will be Seoul 19 C, Incheon 16 C, Suwon 18 C, Chuncheon 20 C, Gangneung 24 C, Cheongju 20 C, Daejeon 19 C, Jeonju 18 C, Gwangju 19 C, Daegu 23 C, Busan 21 C, and Jeju 20 C.
Fine dust concentrations are expected to be "bad" in the greater Seoul area, the Chungcheong region, Gwangju, North Jeolla, and Jeju from the afternoon due to yellow dust carried in on northwesterly winds, and "moderate" in other regions.