Weather Forecast: Cloudy Nationwide with Temperature Variations Up to 15 Degrees

by JINYOUNG PARK Posted : September 12, 2026, 17:28Updated : September 12, 2026, 17:28

On Sunday, September 13, the weather across the country will be mostly cloudy, with the capital region and Gangwon Province remaining overcast until the morning. The temperature difference between day and night is expected to reach up to 15 degrees Celsius in inland areas.

According to the Korea Meteorological Administration, the country will be under the influence of a high-pressure system located over the East Sea. The capital region and Gangwon Province will experience cloudy conditions in the morning, while other areas will see occasional clouds.

From late dawn to morning, light raindrops of less than 0.1 mm are expected in Seoul, Incheon, northern Gyeonggi Province, and central and northern Gangwon Province. In the mountainous areas of Jeju Island, rainfall of 5 to 10 mm is anticipated from the afternoon into the night.

Morning low temperatures are forecasted to range from 12 to 21 degrees Celsius, while daytime highs are expected to be between 23 and 31 degrees. Although temperatures will be similar to the seasonal average, the significant day-night temperature variation of 10 to 15 degrees in inland areas may require attention to health management.

Key morning low temperatures include: Seoul 18 degrees, Incheon 19 degrees, Suwon 17 degrees, Chuncheon 15 degrees, Gangneung 16 degrees, Daejeon 16 degrees, Cheongju 17 degrees, Gwangju 19 degrees, Jeonju 18 degrees, Busan 21 degrees, Ulsan 19 degrees, Daegu 17 degrees, and Jeju 22 degrees.

Expected daytime high temperatures are: Seoul 25 degrees, Incheon 25 degrees, Suwon 25 degrees, Chuncheon 23 degrees, Gangneung 26 degrees, Daejeon 28 degrees, Cheongju 27 degrees, Gwangju 30 degrees, Jeonju 28 degrees, Busan 29 degrees, Ulsan 29 degrees, Daegu 30 degrees, and Jeju 27 degrees.

From early dawn to morning, areas in southern Chungcheong Province, eastern North Jeolla Province, inland South Jeolla Province, inland North Gyeongsang Province, and western inland South Gyeongsang Province may experience fog with visibility of less than 1 km. Roads near rivers, lakes, and valleys may have denser fog, necessitating caution for traffic safety.

Fine dust levels are expected to be at 'good' to 'moderate' levels across all regions due to favorable atmospheric dispersion.

Waves in the East Sea and South Sea are expected to be 0.5 to 1.0 meters, while waves in the West Sea will be around 0.5 meters. In the offshore areas, wave heights are forecasted to be 0.5 to 1.5 meters in the East Sea and South Sea, and 0.5 to 1.0 meters in the West Sea.




* This article has been translated by AI.