jasdooit

This January, marked by a ‘severe cold wave,’ was colder and drier than usual. The national average temperature in January was -1.6°C, 0.7 degrees below the typical level, with rainfall and humidity reaching historic minimums.

As per the ‘Climate Characteristics of January 2026’ report issued by the Korea Meteorological Administration on the 4th, the national average temperature for January, which experienced prolonged severe cold, was -1.6°C. This marked a departure from the recent pattern of ‘milder winters’ driven by global warming. The previous instance when the January average temperature fell below normal was in 2018, eight years prior.

The intense cold experienced in January is surprisingly linked to global warming. The jet stream, which typically keeps cold Arctic air contained, has weakened because of rising temperatures, enabling the frigid Arctic air to regularly move into the Korean Peninsula. Moreover, the ‘blocking phenomenon,’ where atmospheric conditions cause winds to slow down and stagnate, also played a role. Consequently, the Arctic cold air remained over the peninsula, extending the period of cold weather. This situation resulted in temperatures below zero since late last year, leading to the Han River freezing for the first time on January 3rd, seven days earlier than usual.

The arid conditions were also significant. The total precipitation across the country in January was 4.3 mm, less than 20% of the average (26.2 mm). This marked the second-lowest amount recorded since nationwide weather measurements started in 1973. The number of days with rain was 3.7, which is 2.8 days below the usual figure. This is attributed to the dominant northwest winds, which remained cold and dry throughout the month.

The relative humidity also decreased considerably. The national average relative humidity last month was 53%, the smallest ever recorded. Specifically, dry weather alerts continued in Gangwon’s Yeongdong and Gyeongsang areas, where humidity dropped below 50%, more than 10 percentage points below typical levels. The absence of easterly winds, which usually bring moisture, also contributed to this situation.

Even though the number of days with snow was 6.6—close to the usual figure of 6.2—the amount of snow received was less than typical. Although cold temperatures led most rainfall to fall as snow, the overall amount of precipitation was very low.

In comparison, the average sea surface temperature near the Korean Peninsula last month was 12.4°C, the second-highest in the last ten years. This is due to ongoing warming, which has led to more heat being stored in the ocean, along with the continuous flow of warm currents toward Korea. Regionally, the South Sea’s average sea surface temperature reached 16°C, exceeding the recent 10-year average (15.3°C), reaching the highest point. On the other hand, the West Sea’s temperature, significantly affected by Arctic cold air, stayed at 7.1°C, similar to the recent 10-year average.