On Sunday the 21st, the country will see intervals of many clouds with large temperature swings between day and night. In Jeju Island, some areas—mainly east of Hallasan—will see rain starting at night.
According to the Korea meteorological Administration, on the 21st, many clouds will cover the country, including the greater Seoul area. Temperatures will be a bit higher than average, with lows of 13–20 degrees and highs of 23–28 degrees.
Morning lows by major area: ▲ Seoul 20 degrees ▲ Incheon 20 degrees ▲ Suwon 20 degrees ▲ Chuncheon 18 degrees ▲ Gangneung 19 degrees ▲ Cheongju 22 degrees ▲ Daejeon 21 degrees ▲ Jeonju 22 degrees ▲ Gwangju Metropolitan City 22 degrees ▲ Daegu 21 degrees ▲ Busan 23 degrees ▲ Jeju 26 degrees.
Afternoon highs: ▲ Seoul 24 degrees ▲ Incheon 24 degrees ▲ Suwon 24 degrees ▲ Chuncheon 23 degrees ▲ Gangneung 27 degrees ▲ Cheongju 27 degrees ▲ Daejeon 27 degrees ▲ Jeonju 28 degrees ▲ Gwangju Metropolitan City 28 degrees ▲ Daegu 27 degrees ▲ Busan 28 degrees ▲ Jeju 31 degrees.
The Korea meteorological Administration urged caution, noting that inland areas may see large day-to-night temperature differences of around 10 degrees, so people should take care of their health.
Fine dust levels will be "good" nationwide thanks to smooth atmospheric dispersion. In Jeju Island, some areas will see rain through the morning of the 22nd, with expected precipitation of 5–20 mm.
Waves will run 1.0–3.5 meters in the East Sea offing, 0.5–2.0 meters in the West Sea offing, and 0.5–2.5 meters in the South Sea offing.