The highest day temperature in January 2026 was 44°F. The lowest night temperature was 8°F. The average values for day and night temperatures during January were 26.5°F и 20.3°F respectivly.

The average sea surface temperature in January 2026 for Seoul was 37.3°F. The maximum and minimum values were 33.4°F and 41.2°F respectively.

Most of the days in January are sunny but you can also expect cloudy and gloomy days.

Precipitation total in January for Seoul is 0.5 in. It makes january the least rainy month of the year.

The average wind speed in January is 5.7 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Seoul in January is 6.7 hours.