Heavy Rain And Sudden Cold Grip South Korea

As South Korea moved into the third weekend of October 2025, the nation braced for a dramatic shift in weather, marked by heavy rains, plummeting temperatures, and powerful winds sweeping across the peninsula. The Korea Meteorological Administration (KMA) had warned residents to prepare for a weekend of unsettled conditions—a forecast that proved accurate as the skies darkened, rain fell in torrents, and the chill of autumn deepened by the hour.

According to Channel A News, the rain began in earnest across Seoul on October 16, 2025, and was expected to persist through October 19. By the night of October 17, most regions in the south and center of the country were anticipating rainfall amounts between 10 and 50 millimeters, with the southern region experiencing especially intense downpours of around 20 millimeters per hour. The KMA cautioned that rain would continue nationwide on October 18, with the southern and eastern coasts bearing the brunt of the precipitation.

The weather system brought more than just wet conditions. As reported by econovill, the capital and surrounding areas remained overcast throughout October 18, with Seoul’s skies stubbornly refusing to clear. By 11 p.m., the temperature in Seoul had dropped to 15°C, while the probability of further rain remained high at 20%. In Gangwon’s eastern region, rain was relentless, with an 80% chance of showers continuing into the night. Cities like Gwangju, Mokpo, and Yeosu in the Jeolla region also saw intermittent rainfall, with a 60% likelihood of showers, and the same was true for the Gyeongsang region, where Andong, Daegu, and Changwon all experienced rain and cooler temperatures.

Busan, despite its southern latitude, was not spared. The port city saw temperatures dip to around 25°C amid cloudy skies and sporadic rain, while Jeju Island hovered near 23°C with occasional showers. The Chungcheong region was also affected, with heavy rain and thick clouds blanketing cities like Hongseong, Cheongju, and Daejeon. Even as the rain tapered off in some areas, the aftereffects lingered in the form of a sudden cold snap.

“After the rain, the weather turns chilly,” noted weathercaster Ji-Hyun Ma in a Channel A News broadcast. “Nighttime temperatures will drop sharply, and strong winds will sweep across the country.” The impact was immediate: temperatures on October 18 were expected to be 5 to 6 degrees lower than the previous day, a stark reminder of autumn’s arrival. In Seoul, the day began at 16°C and barely reached 19°C at its warmest. Gangneung managed a high of 18°C, while Daegu peaked at 22°C, all significantly cooler than earlier in the week.

By the morning of October 18, much of the country woke to temperatures between 13 and 17°C, with daytime highs ranging from 18 to 21°C in the capital region. According to Gukje News, the cooling trend was expected to intensify as cold air from the north surged in by the afternoon of October 19, sending temperatures plummeting even further. “The wind will be strong, making it feel even colder,” the KMA warned, noting that wind speeds could reach up to 55 kilometers per hour (15 meters per second) in places like Incheon and Gyeonggi Province. In some coastal and mountainous areas, gusts of up to 70 kilometers per hour (20 meters per second) were possible, prompting the issuance of strong wind advisories.

The weekend’s weather was not just about rain and wind; it was also about the first real taste of autumn’s chill. The KMA predicted that the first frost of the season would appear in the mountainous areas of Gangwon, while the central inland regions could see their first patches of ice. In the words of Channel A News, “This weekend marks a turning point, with the weather growing rapidly colder.”

Regional variations were pronounced. In Busan and the broader Gyeongsang area, rain fell overnight into the morning of October 18, with most of it tapering off by afternoon. However, the respite was brief, as light showers and drizzle persisted into the early hours of October 19. Daytime highs in Busan reached just 24°C, while Ulsan and nearby areas hovered around 21°C. Further north, in Daegu and the inland Gyeongbuk region, rain continued through the morning, and the KMA cautioned about reduced visibility and slippery roads due to thunderstorms and gusty winds.

Jeolla’s Gwangju and southern coastal areas experienced strong, sometimes violent rain, with hourly precipitation rates near 20 millimeters in some places. The KMA highlighted the potential for thunder, lightning, and strong gusts, particularly along the west coast and in exposed coastal regions. Jeolla’s morning lows ranged from 17 to 21°C, with daytime highs between 21 and 24°C, but by the following morning, temperatures were expected to dip to 13–17°C, signaling the start of a chillier pattern.

Gangwon Province, meanwhile, remained under a persistent blanket of clouds and rain, with the eastern coast particularly hard hit. Rainfall totals of 10 to 50 millimeters were recorded, and the KMA warned of dangerous surf and high waves along the coast. The region’s mountain areas, such as Daegwallyeong and Taebaek, saw temperatures as low as 11–13°C in the morning, with daytime highs struggling to reach 16–18°C. The cold air influx from the north was expected to bring even lower temperatures and the season’s first frost by Monday.

Jeju Island, renowned for its milder climate, was not immune to the weekend’s wild weather. Rain fell intermittently from late afternoon on October 18, with expected totals between 10 and 60 millimeters. Thunderstorms and gusty winds were forecast, and temperatures, though initially higher than the mainland, began to drop sharply as the cold air mass moved in.

Looking ahead, the KMA warned that the coming days would see continued cold, with temperatures falling below seasonal averages in many areas. Strong winds would persist, especially along the coast and in mountainous regions, making the chill even more pronounced. In Gangwon, the influx of cold air meant that visibility in mountain valleys was reduced by heavy fog, sometimes to less than 200 meters, while coastal areas faced the threat of high waves and dangerous surf.

For South Koreans, the weekend of October 18–19, 2025, was a vivid reminder of nature’s power and unpredictability. From the pounding rain and howling winds to the sudden, biting cold, the weather made its presence felt in every corner of the country. As autumn deepened, residents bundled up, braced for the first frost, and looked to the skies for signs of the next change in the season’s ever-shifting mood.