Last winter was particularly unpredictable, with difficult-to-forecast weather conditions. A sudden cold wave struck, and despite lower-than-expected precipitation, significant amounts of snow fell in various places.
The Korea Meteorological Administration analyzed the characteristics and causes of winter climate from December last year to February this year and announced the results on the 6th. Last winter's temperature was similar to the average, but lower than a year ago, and precipitation was also found to have decreased significantly.
The nationwide average temperature last winter was 0.4 degrees Celsius, which was similar to the average (0.5 degrees) but 2.0 degrees lower than a year ago (2.4 degrees). In particular, there was significant temperature fluctuation in January and February. While temperatures maintained the average early in January, a cold wave arrived in mid-January due to the influence of the Arctic oscillation. The Arctic oscillation refers to the phenomenon where cold air vortexes existing in the Arctic alternate in strength over periods of decades or longer. Following this, temperatures surged rapidly under the influence of a warm migratory high-pressure system. In Seoul, for instance, the lowest temperature was -9.7 degrees on January 9, and the highest was 5.2 degrees on January 25, showing a significant daily temperature difference of 14.9 degrees. Anomalous warm weather occurred on six days: January 14, 19, and from 22 to 25.
February saw an unusual cold snap. The 'Ural blocking' phenomenon formed due to a North Atlantic storm, which blocked the flow of air from the Ural Mountains, leading to sustained strong cold spells for more than a week during the periods of Iphun (February 3-10) and Usul (February 18-24). Consequently, the average temperature in February was -0.5 degrees, which was 1.7 degrees lower than the average and the lowest recorded in the past decade.
The nationwide average precipitation last winter was 39.6 mm, which was only 43.6% of the average and recorded the fourth-lowest amount in history. Compared to a year ago (236.7 mm), it was only one-sixth.
Despite the frequent chilly north winds leading to low precipitation, snow fell often, especially in the western regions. The nationwide average number of snowy days was 21.9, which was 6.0 days more than the average, ranking fourth in history. Notably, a lot of snow fell in the metropolitan area and the Chungcheong and Jeolla regions during the Lunar New Year holiday (January 27-29). However, the total amount of snow that fell over the three months (27.4 cm) was similar to the average (25.9 cm).
The sea surface temperature around the Korean Peninsula during winter was on average 12.4 degrees, which was 0.2 degrees higher than the recent ten-year average. This is the second-highest figure in the last ten years, with 2019 recording the highest at 12.8 degrees. In December and January, the temperatures were 15.3 degrees and 12.1 degrees, respectively, higher than the average, but in February, it was 9.9 degrees, which was 0.4 degrees lower.
Korea Meteorological Administration head Jang Dong-eon noted, "The snowfall and rain during the Samil holiday alleviated some of the dryness in the atmosphere, but there is still a high risk of wildfires in spring, so thorough preparedness is necessary," and added, "Last winter also saw fluctuating climates, including anomalous warm temperatures and late winter cold snaps, and there is a possibility that climate variability will intensify in the future. The Korea Meteorological Administration will closely monitor unusual climates and do our best to provide prompt information to ensure the safety of the public."