On September 26, 2026, weather across the Korean Peninsula delivered a dramatic mix of heavy rainfall, shifting temperatures, and warnings for both land and sea, as millions marked the third day of the Chuseok holiday. From the southern coastlines of South Korea to the northern reaches of North Korea, meteorologists warned of fast-changing skies, localized downpours, and even historic climate anomalies, keeping residents and travelers on alert.
According to IMBC, rain was forecast to concentrate mainly in South Korea’s southern regions and Jeju Island, with the Jeonnam (South Jeolla) coastal area bracing for up to 80 millimeters of rainfall, accompanied by gusty winds and the threat of thunder and lightning. This deluge prompted expanded heavy rain warnings early in the morning, as reported by YTN, with areas such as Muan, Heuksando, Hongdo, Wando, Geomundo, and Chodo all placed on alert. The broadcaster noted, "Currently, strong rain is ongoing on the Jeonnam coast with heavy rain warnings expanded to areas including Muan, Heuksando, Hongdo, Wando, Geomundo, and Chodo."
For those rising early, the day began with a chill in the air—morning low temperatures across South Korea ranged from 6 to 20 degrees Celsius, depending on the region. IMBC reported the coldest start at 6 degrees, while other areas saw lows as high as 20 degrees, according to Shin-A Ilbo. As the day progressed, however, the country’s temperature map became a patchwork of contrasts. Central regions, including Seoul, cleared up and heated rapidly, with the capital expected to reach a balmy 27 degrees Celsius. Meanwhile, southern areas and Jeju Island remained under persistent cloud cover and rain, keeping daytime highs more modest—Busan, for instance, was forecast to top out at 24 degrees.
Rainfall projections varied dramatically by region. The Korea Meteorological Administration, cited by Shin-A Ilbo, broke down the expected precipitation: 5 to 10 millimeters in Seoul, Incheon, Gyeonggi, Daegu, and Gyeongbuk (excluding the eastern coast); 5 to 20 millimeters in Gangwon, Daejeon, Sejong, Chungnam, Chungbuk, Busan, Ulsan, and Gyeongnam (excluding the west); and much heavier amounts in the southwest, with Gwangju and inland Jeonnam expecting 10 to 60 millimeters, Jeonnam coast up to 80 millimeters, Jeonbuk 5 to 40 millimeters, and Jeju Island potentially seeing 20 to 80 millimeters. The broadcaster YTN emphasized, "Heavy rain is expected until 9 AM on the Jeonnam coast, with up to 80 millimeters in Jeonnam coastal areas and up to 60 millimeters in Jeju Island."
As for the sea, rough conditions were forecast for offshore waters, especially in the southern West Sea and around Jeju. Shin-A Ilbo detailed that waves would reach 0.5 to 1.5 meters in the East and South seas and 0.5 to 1.0 meters in the West Sea, while farther out—up to 200 kilometers from shore—wave heights could soar to 3 meters, prompting storm warnings for mariners and coastal residents alike.
Amid these shifting conditions, the Chuseok holiday's third day saw families and travelers adjusting their plans. Many in central regions, where the rain cleared early, took advantage of the return of warmth and sunshine, while those in the south and on Jeju Island kept umbrellas at the ready.
North of the border, North Korea faced its own meteorological complexities. According to reports from Chosun Central TV and Yonhap News, the northern part of the country was under the influence of both high and low pressure systems, resulting in sporadic rainfall of 1 to 20 millimeters, particularly in the north. The North Korean Meteorological and Hydrological Bureau forecasted that Baekdu Mountain would start the day at a frigid 0 degrees Celsius, while daytime highs could soar to 29 degrees in the Paechon area—a striking temperature swing.
Weather forecasts for major North Korean cities painted a diverse picture: Pyongyang was expected to be mostly clear, with some morning cloudiness and a 60% chance of rain, reaching 25 degrees Celsius. Other cities showed similar variability: Junggang was forecast for 18 degrees with a 60% chance of rain; Haeju and Kaesong were expected to be sunny and warm at 26 and 27 degrees, respectively, with no rain; Hamhung would be clear and 24 degrees; while Chongjin faced clouds, a chance of rain, and a high of 20 degrees.
Looking ahead, North Korean authorities warned that from September 27 to October 2, the northern regions could experience 2 to 30 millimeters of rain and even hail. Starting October 1, overall temperatures were expected to dip below seasonal averages, with frost predicted in some areas north of the central region. This warning came on the heels of a remarkable week in North Korea, where the average temperature and sunshine duration hit record highs since observations began, while precipitation was less than 1 millimeter—the lowest ever recorded.
For coastal and maritime communities, the sea presented its own set of hazards. Shin-A Ilbo and YTN both cautioned that the southern West Sea and Jeju offshore would see the roughest conditions, with the potential for waves up to 3 meters and the risk of storm surges. These warnings were not just theoretical—fishermen, ferry operators, and holidaymakers were urged to stay vigilant and heed local advisories.
Meanwhile, YTN briefly noted that even the Asian Games city of Nagoya, Japan, was experiencing heavy rain and a flood advisory on September 26, a reminder that the region’s unsettled weather was not confined to the Korean Peninsula alone.
Despite the inclement weather, the Chuseok holiday spirit endured. In central South Korea, the clearing skies and warming temperatures allowed many to continue with family gatherings, ancestral rites, and outings. Yet in the south, where the rain persisted into the afternoon and evening, plans were more subdued, and many found themselves watching the skies or checking their phones for the latest weather updates.
In summary, September 26, 2026, was a day of contrasts and caution across Korea. From heavy rain and storm warnings on the southern coast to record-breaking warmth and historic drought in the north, the weather underscored both the region’s natural diversity and the unpredictability that can come with the changing seasons. As meteorologists continued to monitor the skies, residents and visitors alike were reminded of the value of preparation—and perhaps the wisdom of keeping an umbrella close at hand, just in case.