From T-shirts to padded jackets: Why Korea's October weather swung so wildly

Korea experienced sharp temperature swings in October as Ural blocking over Russia disrupted weather patterns and allowed cold Arctic air to move south toward the peninsula. The nationwide gap between the warmest and coldest daily average temperatures reached 14 degrees Celsius, the fourth-largest October fluctuation on record. Seoul reached 30.1 degrees on Oct. 12, then temperatures fell nationwide to 8.1 degrees on Oct. 28. The blocking pattern also contributed to heavy late-month rainfall, while rain and another cold-air surge were forecast for early November.

The Korea Meteorological Administration released its analysis of October’s climate conditions on Wednesday.

The nationwide daily average temperature was 22.1 degrees on Oct. 12 and 8.1 degrees on Oct. 28.

Nationwide precipitation totaled 108.5 millimeters, about 1.7 times the 1991–2020 average, with 108 millimeters falling after mid-October.

The country averaged 4.3 rainy days during the final third of October, the highest figure on record for that period.

An unusually strong El Niño, with central and eastern equatorial Pacific sea-surface temperatures more than 2 degrees above normal, also influenced regional atmospheric circulation.

Published Nov 4, 2026 5:57 pm KST

Foreign tourists wearing padded jackets watch a reenactment of a royal guard inspection ceremony at Gyeongbok Palace in Jongno District, Seoul, Oct. 29. Yonhap

Koreans went from wearing short sleeves to pulling out padded winter jackets last month as temperatures swung dramatically between summer-like heat and early winter chills. The reason, meteorologists say, was a massive high-pressure system thousands of kilometers away over Russia's Ural Mountains.

The atmospheric phenomenon, known as "Ural blocking," disrupted the usual flow of weather systems, allowing cold Arctic air to surge south toward the Korean Peninsula. Scientists say rapid warming in the Arctic may have helped intensify the disruption by weakening the jet stream that normally helps contain frigid air in northern latitudes.

The Korea Meteorological Administration (KMA) released its analysis of October's climate conditions on Wednesday, identifying extreme temperature variability as the month's defining characteristic.

The difference between the warmest and coldest daily average temperatures nationwide reached 14 degrees Celsius, the fourth-largest October fluctuation on record. The average temperature stood at 22.1 degrees on Oct. 12 before plunging to 8.1 degrees on Oct. 28.

Seoul experienced an especially remarkable burst of heat on Oct. 12, when the daytime high reached 30.1 degrees Celsius, making it the hottest October day in the capital since modern weather observations began in 1907.

A foreign tourist wearing a short-sleeved shirt walks through Gwanghwamun Square in Seoul on Oct. 12. Yonhap

Temperatures then fluctuated sharply. The nationwide daily average fell from 19.8 degrees Celsius on Oct. 18 to 9.8 degrees just four days later. It rebounded to 16.9 degrees on Oct. 25 before plunging again to 8.1 degrees three days later, bringing an early taste of winter.

How weather system over Russia sent cold air into Korea

The dramatic swings were driven by changes in atmospheric circulation.

In mid-October, warm air flowed into Korea along a high-pressure circulation pattern in the upper atmosphere. Later in the month, however, a persistent high-pressure system developed over northern Europe and the Ural Mountains, creating a blocking pattern that disrupted the normal west-to-east movement of weather systems.

The disruption allowed cold air to move rapidly southward over the Korean Peninsula.

"When Ural blocking occurs, low-pressure troughs carrying cold air frequently move down toward Korea, causing sudden cold spells," said Lee Myong-in, a professor at Ulsan National Institute of Science and Technology.

Alternating warm and cold spells are common in autumn as high- and low-pressure systems pass over the peninsula. But the blocking pattern made October's cold spells particularly intense.

Scientists point to Arctic warming as one possible factor behind the stronger blocking.

The jet stream, a band of powerful winds high in the atmosphere, normally acts as a barrier that helps keep Arctic cold air confined to northern regions. As the Arctic warms rapidly and ice melts, the temperature difference between the polar region and lower latitudes narrows, potentially weakening the jet stream.

A weaker jet stream can develop larger north-south bends, slowing the movement of weather systems and allowing persistent blocking patterns to form.

The blocking pattern also contributed to unusually frequent rainfall during the second half of October.

Nationwide precipitation totaled 108.5 millimeters, about 1.7 times the average for the 1991–2020 period. Nearly all of it — 108 millimeters — fell after the middle of the month. The country recorded an average of 4.3 rainy days during the final third of October, the highest figure on record for that period.

An unusually strong El Niño, with sea surface temperatures in the central and eastern equatorial Pacific more than 2 degrees above normal, also influenced regional atmospheric circulation. Reduced convection over the western Pacific helped a high-pressure system develop southeast of Korea.

Warm, moisture-laden air moving along the edge of that system collided with cold air drawn south by the blocking pattern, producing rain clouds over the peninsula.

The unsettled weather is expected to continue into early November.

Rain is forecast across the country on Thursday, with around 5 millimeters expected in the Seoul metropolitan area, 5 to 20 millimeters in the Chungcheong provinces and North Gyeongsang Province, and 10 to 40 millimeters in the Jeolla provinces, South Gyeongsang Province and Jeju Island.

Once the rain clears, another surge of cold air is expected to send temperatures sharply lower.

On Nov. 7, which marks "Ipdong," the traditional Korean calendar's beginning of winter, morning lows are forecast to range from minus 4 to 5 degrees Celsius nationwide. Seoul is expected to drop to minus 1 degree, marking the capital's first subzero temperature of the autumn season.

This article from the Hankook Ilbo, the sister publication of The Korea Times, was translated by a generative AI system and edited by The Korea Times.

10月份，受俄罗斯上空乌拉尔阻塞高压的影响，韩国气温剧烈波动。阻塞高压扰乱了天气系统，导致北极冷空气南下侵袭朝鲜半岛。全国最高气温与最低气温的日均温差达到14摄氏度，创下10月份气温波动幅度第四大的历史纪录。10月12日，首尔气温高达30.1摄氏度，随后全国气温在10月28日骤降至8.1摄氏度。阻塞高压还导致了月底的强降雨，预计11月初还将迎来降雨和另一波冷空气。

韩国气象厅周三发布了10月份气候状况分析报告。

10 月 12 日全国平均气温为 22.1 度，10 月 28 日为 8.1 度。

全国降水量总计 108.5 毫米，约为 1991-2020 年平均值的 1.7 倍，其中 108 毫米降水发生在 10 月中旬之后。

10 月最后三分之一月份，该国平均降雨天数为 4.3 天，创下同期历史最高纪录。

异常强烈的厄尔尼诺现象，导致中东部赤道太平洋海面温度比正常水平高出 2 度以上，也影响了区域大气环流。

发布于2026年11月4日下午5:57（韩国标准时间）

10月29日，在首尔钟路区景福宫，身穿羽绒服的外国游客观看皇家卫队检阅仪式的重现表演。（韩联社）

上个月，韩国气温骤降，从夏日般的炎热骤降至初冬的寒冷，人们纷纷从穿着短袖转为穿上厚厚的冬装。气象学家表示，造成这种现象的原因是数千公里外俄罗斯乌拉尔山脉上空存在一个巨大的高压系统。

这种被称为“乌拉尔阻塞”的大气现象扰乱了正常的天气系统流动，使得寒冷的北极空气得以南下，直扑朝鲜半岛。科学家表示，北极地区的快速变暖可能加剧了这种扰乱，因为它削弱了通常有助于将寒冷空气限制在北纬地区的急流。

韩国气象厅（KMA）周三发布了对10月份气候状况的分析，指出极端气温变化是该月的主要特征。

全国每日平均气温最高值与最低值之间的温差达到14摄氏度，这是有记录以来10月份第四大的温差。10月12日平均气温为22.1摄氏度，随后在10月28日骤降至8.1摄氏度。

10 月 12 日，首尔经历了异常高温，白天最高气温达到 30.1 摄氏度，成为自 1907 年现代气象观测开始以来首都 10 月份最热的一天。

10月12日，一名身穿短袖衬衫的外国游客走过首尔光化门广场。（韩联社）

随后气温剧烈波动。全国日均气温从10月18日的19.8摄氏度骤降至四天后的9.8摄氏度。10月25日回升至16.9摄氏度，三天后再次暴跌至8.1摄氏度，提前带来了冬季的寒意。

俄罗斯上空的天气系统如何将冷空气输送到韩国

这种剧烈的波动是由大气环流的变化引起的。

10月中旬，暖空气沿着高空高压环流流入韩国。然而，当月晚些时候，北欧和乌拉尔山脉上空形成了一个持续的高压系统，构成阻塞高压，扰乱了天气系统正常的自西向东移动。

这次扰动使得冷空气迅速向南移动，覆盖了朝鲜半岛。

“当乌拉尔阻塞发生时，携带冷空气的低压槽经常向韩国移动，导致突然的寒流，”蔚山科学技术大学教授李明仁说。

秋季，随着高低气压系统在半岛上空移动，冷暖交替的天气十分常见。但阻塞高压系统使得十月份的寒潮尤为强烈。

科学家指出，北极变暖可能是导致阻塞高压增强的因素之一。

喷射气流是大气层高处的一股强劲气流，通常起到屏障作用，将北极的冷空气限制在北部地区。随着北极快速变暖和冰川融化，极地地区与低纬度地区之间的温差缩小，这可能会削弱喷射气流。

较弱的喷射气流会形成更大的南北向弯曲，减缓天气系统的移动，并导致持续阻塞模式的形成。

阻塞高压模式也导致了10月下半月异常频繁的降雨。

全国总降水量为108.5毫米，约为1991年至2020年平均降水量的1.7倍。其中几乎全部（108毫米）都集中在10月中旬之后。10月下旬，全国平均降雨天数为4.3天，创下同期历史新高。

异常强烈的厄尔尼诺现象导致中东太平洋赤道海域海面温度比正常水平高出2摄氏度以上，也影响了区域大气环流。西太平洋对流减弱，促使韩国东南部形成高压系统。

沿该系统边缘移动的温暖潮湿空气与受阻塞形势影响而向南移动的冷空气相遇，在半岛上空形成了雨云。

预计不稳定天气将持续到11月初。

预计周四全国将有降雨，首尔都市圈降雨量约为 5 毫米，忠清道和庆尚北道降雨量为 5 至 20 毫米，全罗道、庆尚南道和济州岛降雨量为 10 至 40 毫米。

雨停后，预计另一股冷空气将使气温急剧下降。

11月7日是韩国传统历法中的“益洞”，标志着冬季的开始。预计全国早晨最低气温将在零下4至5摄氏度之间。首尔预计将降至零下1摄氏度，这将是该市秋季以来首次出现零下气温。

本文来自《韩国日报》（《韩国时报》的姊妹报），由人工智能生成系统翻译，并由《韩国时报》编辑。