December Weather in Seoul, South Korea

Last updated: October 30, 2025

December in Seoul, South Korea presents a chilly yet captivating atmosphere, with average temperatures hovering around -1°C (31°F). The month sees a maximum temperature of 12°C (54°F) and chilling lows that can plunge to -15°C (5°F), making it essential to bundle up. While a modest 22 mm (0.9 in) of precipitation falls across approximately 4 days, the city's humidity levels sit at a notable 74%, contributing to the crisp winter air. This season paints Seoul in a stunning winter landscape, perfect for those seeking to experience its unique charm and festive spirit.

December Temperature in Seoul

As December approaches in Seoul, South Korea, the city settles into its winter chill, showcasing a significant drop in temperatures compared to previous months. With a minimum temperature dipping to -15°C (5°F) and an average hovering around -1°C (31°F), the early signs of winter are unmistakable. As the month progresses, high temperatures reach a peak of 12°C (54°F), offering brief moments of respite from the cold. This trend marks a transition from the more moderate conditions experienced in autumn, with November's average temperature at 7°C (45°F), clearly highlighting the arrival of winter. Visitors can expect a brisk atmosphere, perfect for embracing Seoul's cozy cafés and festive winter decorations.

December Weather in Seoul: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Seoul, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Seoul, December typically has an average temperature of -1°C (31°F), with highs reaching up to 12°C (54°F) and lows dropping to around -15°C (5°F).
JanFebMarAprMayJunJulAugSepOctNovDec283244546472797970584531
Data source: Temperature data for Seoul generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Seoul

December in Seoul, South Korea, wraps up the year with relatively modest precipitation, averaging 22 mm (0.9 in) over just 4 days of rain. This marks a slight increase from the autumn months of November and October, where rainfall was heavier, but still significantly lower than the summer months that feature torrential downpours. As the city transitions into winter, the precipitation subsides, creating drier conditions while temperatures continue to drop. The pattern reflects a broader seasonal trend in Seoul, where rainfall peaks during the summer and tapers off as the year winds down, paving the way for a crisp and clear winter landscape.

December Precipitation Trends in Seoul

The chart displays monthly precipitation patterns in Seoul, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Seoul, December typically receives around 22 mm (0.9 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec1922465511186253269133635422
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Seoul

As autumn fades, December humidity in Seoul settles at 74%, marking a noticeable shift as the year draws to a close. This month showcases a decrease from the 80% average of November, offering a brief respite before winter fully takes hold. Throughout the year, Seoul experiences a distinct trend, with humidity peaking during the summer months of July and August at an impressive 91%. Conversely, winter months like January maintain higher humidity levels around 71%. Overall, December marks a transitional phase, as the city prepares for drier, colder months ahead while retaining a significant level of moisture in the air.

December Average Humidity in Seoul

This chart illustrates the average monthly humidity levels in Seoul, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Seoul is approximately 74%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec71%65%65%75%81%85%91%91%77%79%80%74%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Seoul

As December unfolds in Seoul, South Korea, the UV Index dips to a moderate level of 3, with a burn time of approximately 30 minutes. This drop marks a contrast to the extreme UV exposure seen during the summer months, where values soared to 11 in July and August. Notably, the transition from the lingering high indices of late spring and early summer to December's gentle rays reveals a seasonal pattern that encourages outdoor enjoyment without the relentless sun. As the year closes, sunlight is more forgiving, providing a perfect opportunity to savor the city's winter landscape without excessive worry about sunburn. For detailed UV Index insights throughout the year, visit Seoul UV Index.

Maximum UV Index Levels in Seoul for December

The chart shows the monthly maximum UV Index (UVI) for Seoul in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Seoul typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec346891011119643
Data source: Seoul December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

December Sunshine in Seoul

December in Seoul experiences a cozy dip in sunshine, with 235 hours of radiant daylight. This marks a gentle decline from the brighter months, peaking in June with 317 hours. Interestingly, as the year draws to a close, the city's sunlight remains fairly consistent compared to November's 231 hours, embodying a warm, inviting atmosphere during the chill of winter. This trend reflects a gradual transition from the vibrant, sun-soaked days of summer, where the city basks in over 300 hours of sunshine from May through June, to the more subdued glow of December, where each sunbeam offers a touch of warmth against the cold backdrop of the season.

Monthly Sunshine Duration in Seoul: December Highlighted

The December sunshine duration represents the total number of hours Seoul experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec199h242h282h287h311h317h294h289h262h263h231h235h
Data source: Seoul December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Seoul During December

As December unfolds in Seoul, South Korea, the likelihood of basking in sunny weather reaches a notable 64%. This marks a significant uptick compared to previous months, showcasing a trend where late autumn gives way to clearer skies. Notably, December's chances surpass those of January and February, which both sit at 55%. The clouds of earlier months are gradually replaced by sunshine, creating a perfect backdrop for the festive spirit of the holiday season. Such statistics not only highlight the optimism for brighter days ahead but also encourage outdoor activities and celebrations against the crisp winter air. Overall, December stands out as a hopeful month for sun seekers in the bustling city.

Percentage of Sunny Days in December in Seoul

The chart illustrates the percentage of sunny days in Seoul throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Seoul experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec55%55%43%44%37%36%30%30%41%43%58%64%
Data source: Seoul December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Seoul in December

As December arrives in Seoul, South Korea, daylight takes a dip to 9 hours, mirroring the brisk chill of winter. This trend of decreasing illumination begins in November, where daylight is slightly longer at 10 hours, and culminates in the shortest days of the year. Following a gradual ascent from January's 9 hours to April's 13 hours, the city experiences its annual peak of daylight in May and June, when the duration stabilizes at 14 hours. However, as summer fades into fall, the daylight hours wane steadily. By the end of the year, the contrasting dynamics between shorter winter days and longer summer days illustrate the captivating rhythm of Seoul's seasonal light cycle, underscoring the city's unique climatic character.

Average Daylight Hours in Seoul for December

The chart illustrates the variation in daylight duration in Seoul throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 53m10h 47m11h 57m13h 9m14h 10m14h 40m14h 25m13h 32m12h 23m11h 12m10h 9m9h 37m
Data source: Seoul daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Seoul

In December, the wind in Seoul picks up slightly, averaging 2.7 m/s (6 mph), a refreshing change as the city transitions to winter. This increase in wind speed is a subtle farewell to the milder breezes of late fall, which hovered around 2.4 m/s in November. As temperatures drop, the brisk December air invigorates the bustling streets, encouraging locals and visitors alike to wrap up warmly and embrace the seasonal charm. Looking back over the year, December’s winds are consistent with the slight fluctuations seen since summer, where July recorded the calmest days with only 1.8 m/s (4 mph). Overall, December's breezes signal the arrival of colder months, blending seamlessly into Seoul's vibrant winter atmosphere.

Average December Wind Speed in Seoul

The chart displays monthly wind speed patterns in Seoul, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.83.12.52.72.62.01.82.22.42.22.42.7 m/s
Data source: Seoul December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Seoul Compares to Other Months

Weather in Seoul varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Seoul, focusing on differences in temperature, rainfall, humidity, and UV levels.

In December, the weather typically features a minimum temperature of -15°C (5°F) and averages around -1°C (31°F), with a maximum reaching up to 12°C (54°F). The month sees about 22 mm (0.9 in) of precipitation over 4 days, along with a humidity level of 74%. In contrast, January is a bit colder, with minimum temperatures dropping to -18°C (1°F) and an average of -2°C (28°F), while the maximum temperature slightly increases to 13°C (55°F). Precipitation in January is slightly lower at 19 mm (0.8 in) over just 2 days, contributing to a slightly drier atmosphere with a humidity of 71%. For more details, you can check out Seoul weather in January.

December and February present a notable contrast in weather, with both months experiencing cold temperatures but offering different atmospheres. In December, temperatures range from a minimum of -15°C (5°F) to a maximum of 12°C (54°F), with an average of -1°C (31°F) and a relatively higher humidity of 74%. Precipitation remains consistent at 22 mm (0.9 in) over four days, often resulting in a chilly, damp feel.

On the other hand, February sees slightly milder conditions, with temperatures ranging from a minimum of -14°C (7°F) to a maximum of 18°C (65°F) and a daytime average of 0°C (32°F). The month also experiences lower humidity at 65%, providing a crisper feel to the air. Precipitation levels remain similar at 22 mm (0.8 in) over four days, but the weather can feel much more pleasant compared to December. For a detailed overview of the conditions, check out Seoul weather in February.

In December, the weather is quite chilly, with temperatures ranging from a minimum of -15°C (5°F) to a maximum of 12°C (54°F) and an average of -1°C (31°F). The month sees about 22 mm (0.9 in) of precipitation over four days, accompanied by a relatively high humidity of 74%. In contrast, March offers a significant warming trend, with minimum temperatures of -7°C (20°F) and maximums reaching 21°C (70°F), averaging around 7°C (44°F). Precipitation increases to 46 mm (1.8 in) over five days, but humidity decreases to 65%. This transition from December to March showcases a clear shift from cold winter conditions to the more moderate and invigorating spring weather. For more detailed insights on March weather, you can visit Seoul weather in March.

December and April present quite a contrast in weather conditions. In December, temperatures can dip as low as -15°C (5°F) with an average of -1°C (31°F) and a maximum of 12°C (54°F), creating a chilly atmosphere with a humidity level of 74%. Precipitation is relatively low at 22 mm (0.9 in) over 4 days. In contrast, April brings a much milder climate, with temperatures ranging from a minimum of 0°C (32°F) to a maximum of 28°C (82°F) and an average of 12°C (54°F). This spring month experiences increased rainfall, totaling 55 mm (2.2 in) over 6 days, while the humidity remains similar at 75%. For more detailed insights into April weather, check Seoul weather in April.

December and May present stark contrasts in weather patterns. In December, temperatures can plummet to a minimum of -15°C (5°F) and generally hover around an average of -1°C (31°F), while the maximum rarely exceeds 12°C (54°F). This month also experiences relatively low precipitation, with just 22 mm (0.9 in) over about 4 days and humidity levels at 74%. In contrast, May brings a significant warming trend, with minimum temperatures of 6°C (43°F) and an average high of 18°C (64°F), peaking at a maximum of 32°C (89°F). Rainfall increases substantially to 111 mm (4.4 in) over 9 days, matched by higher humidity at 81%. This transition highlights the shift from the chill of winter to the warmth of late spring. For more details on May weather, you can check Seoul weather in May.

December and June present stark contrasts in weather conditions. In December, temperatures range from a chilling -15°C (5°F) to a mild 12°C (54°F), with an average of -1°C (31°F). The month experiences relatively low precipitation of 22 mm (0.9 in) over just 4 days, and humidity sits at 74%. In contrast, June brings much warmer weather, with temperatures ranging from 12°C (54°F) to a sizzling 35°C (94°F) and an average of 22°C (72°F). The month is also wetter, receiving 86 mm (3.4 in) of precipitation across 8 days, along with higher humidity levels of 85%. For a closer look at June's weather patterns, check out Seoul weather in June.

December and July in Seoul present a stark contrast in weather conditions. In December, temperatures drop to a minimum of -15°C (5°F) and usually average around -1°C (31°F), with a maximum of 12°C (54°F). The month sees relatively low precipitation at 22 mm (0.9 in) over just 4 days, accompanied by a humidity level of 74%. In contrast, July boasts much warmer temperatures, with a minimum of 18°C (64°F), an average of 26°C (79°F), and a maximum of 36°C (97°F). This summer month experiences significantly higher precipitation at 252 mm (9.9 in) over 15 days, and humidity levels rise to 91%, creating a more oppressive atmosphere. For more details, check out Seoul weather in July.

December and August showcase stark contrasts in weather conditions. December's temperatures can dip to a chilling minimum of -15°C (5°F) with an average around -1°C (31°F), while August boasts a much warmer average of 26°C (80°F) and can reach up to a scorching 38°C (101°F). Precipitation further highlights the differences: December experiences a modest 22 mm (0.9 in) over just 4 days, whereas August sees significantly higher rainfall of 269 mm (10.6 in) across 16 days, accompanied by much higher humidity levels of 91%. For a more detailed look, you can check Seoul weather in August.

December and September present stark contrasts in weather patterns. In December, temperatures can plummet to a minimum of -15°C (5°F), with an average around -1°C (31°F) and a maximum of 12°C (54°F). The month sees a relatively low precipitation level of 22 mm (0.9 in) over just 4 days, with humidity at 74%. In contrast, September boasts much milder conditions, with temperatures ranging from a minimum of 10°C (50°F) to a maximum of 31°C (88°F) and an average of 21°C (70°F). The month is also much wetter, receiving 133 mm (5.2 in) of rain across 9 days, and maintaining a slightly higher humidity level of 77%. For more detailed information, check out Seoul weather in September.

In December, the weather is significantly colder, with temperatures ranging from a minimum of -15°C (5°F) to a maximum of 12°C (54°F) and an average of -1°C (31°F). In contrast, October boasts milder temperatures, with a minimum of 0°C (32°F), an average of 14°C (58°F), and a maximum of 28°C (83°F). While December experiences less precipitation, measuring only 22 mm (0.9 in) over about 4 days, October has a higher level of rainfall at 63 mm (2.5 in) spread over 6 days. Additionally, humidity levels are slightly higher in October at 79%, compared to December’s 74%. For a detailed look at October weather patterns, you can visit Seoul weather in October.

In December, temperatures in Seoul experience a more pronounced chill, with a minimum of -15°C (5°F) and an average of -1°C (31°F), considerably lower than November's averages which range from a minimum of -7°C (21°F) to a milder average of 7°C (45°F). While December's maximum temperature can reach 12°C (54°F), November boasts a higher peak at 21°C (70°F). Additionally, December sees lower precipitation levels at 22 mm (0.9 in) over 4 days, contrasted with November's higher rainfall of 54 mm (2.1 in) across 5 days. Humidity is also somewhat lower in December at 74%, compared to November's 80%. For a detailed view of November weather patterns, visit Seoul weather in November.

Compare Seoul's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Seoul

As December settles over Seoul, the city experiences a notable transformation in its climate. Temperatures take a dip, with averages hovering around a chilly -1°C (31°F), contrasting sharply with the milder autumn months. This month also sees a slight increase in humidity, averaging 74%, creating a crisp atmosphere that wraps the city in winter's embrace. While precipitation is minimal, occurring only a few days, the air feels distinctly different, heralding the onset of colder days ahead. For those looking to explore Seoul's winter charm, understanding the seasonal shifts is crucial; find more insights at Seoul Climate.