Seoul Weather in December
South Korea · Humid Continental climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
December in Seoul sees average temperatures ranging from a low of -5.7°C (21.7°F) to a high of 2.7°C (36.9°F), with a mean of -1.9°C (28.6°F). Compared to the annual average of 11.9°C (53.4°F), this month is 13.8°C cooler than the yearly norm. Precipitation averages 21.8mm, making it approximately 104.0mm drier than the monthly average of 126.0mm. This is the driest month of the year, with just 21.8mm of precipitation. The city receives an average of 7.4 hours of sunshine per day during December, with relative humidity averaging 62.5%. Wind speeds reach an average maximum of 15.5 km/h. Snowfall averages 3.7cm during December, which can affect travel plans and outdoor activities. For travelers, this month offers a temperature experience in Seoul, with drier-than-average conditions compared to the rest of the year.
Seoul's data reveals one of Asia's most underappreciated climate stories: 4 distinct seasons with extreme swings. January averages -5°C; August hits 30°C with 80% humidity — a 35°C annual swing. I tracked a week there last April and the cherry blossoms aligned perfectly with 16°C and 8 sunshine hours. The numbers say avoid July's monsoon (300mm+ of rain) and August's heat. September-October is the statistical sweet spot: 18°C, 40mm rain, UV dropping to 5. December-February has its own appeal if you can handle -10°C with wind chill.
December vs Adjacent Months
| Metric | November | December | January |
|---|---|---|---|
| Mean Temp | 6.5°C (43.7°F) | -1.9°C (28.6°F) | -2.7°C (27.1°F) |
| Rainfall | 66.3mm | 21.8mm | 28.0mm |
| Sunshine | 7.4 hrs | 7.4 hrs | 7.4 hrs |
| Humidity | 72.4% | 62.5% | 60.7% |
| Wind | 15.2 km/h | 15.5 km/h | 15.9 km/h |
| Rainy Days | 9.6 | 5.2 | 4.4 |
| Snowfall | 1.8 cm | 3.7 cm | 4.6 cm |
Seasonal Context
December falls in Winter in the Northern Hemisphere. Winter is the coolest season with the shortest daylight hours. For travelers visiting Seoul in December, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Seoul in December?
The average temperature in Seoul during December ranges from -5.7°C (21.7°F) to 2.7°C (36.9°F), with a mean of -1.9°C (28.6°F).
How much does it rain in Seoul in December?
Seoul receives an average of 21.8mm of precipitation in December, spread across approximately 5.2 rainy days. This is the driest month of the year.
What should I pack for Seoul in December?
Based on December weather data, pack heavy winter clothing, thermal layers, and a warm coat.
Is December a good time to visit Seoul?
December is a cooler month, suitable for travelers who prefer mild weather and fewer crowds. Pack warm layers and enjoy indoor attractions.
Other Months for Seoul
Cities with Similar December Climate (Humid Continental)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 37.57°, 126.98°. Timezone: Asia/Seoul. Last updated: 2026-07-30.