December Weather in Osan, South Korea

Last updated: October 30, 2025

December in Osan, South Korea is characterized by a cool, brisk climate as temperatures fluctuate, with a maximum reaching 13°C (56°F) and an average hovering around 0°C (33°F). As winter sets in, the thermometer can dip as low as -14°C (8°F), creating a stark contrast that shapes the month’s chilly atmosphere. The city sees 26 mm (1.0 in) of precipitation over five days, contributing to a humidity level of 74% that often enhances the winter chill. This blend of cold temperatures and occasional moisture creates a quintessential winter experience worthy of exploration.

December Temperature in Osan

In December, Osan, South Korea, embraces the heart of winter with temperatures that typically range from a chilly -14°C (8°F) at night to a daytime average of 0°C (33°F). As the year draws to a close, residents experience stark contrasts between the biting cold of early winter and the relatively mild days, where highs can reach up to 13°C (56°F). This month marks a definitive shift from the preceding autumn, with temperatures trending lower, showcasing a gradual decline that started in November. The landscape, often blanketed in frost, serves as a picturesque backdrop, inviting both locals and visitors to enjoy seasonal festivities under a crisp, clear sky.

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

The chart illustrates December temperature patterns in Osan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Osan, December typically has an average temperature of 0°C (33°F), with highs reaching up to 13°C (56°F) and lows dropping to around -14°C (8°F).
JanFebMarAprMayJunJulAugSepOctNovDec293244546472798071594632
Data source: Temperature data for Osan generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Osan

December in Osan, South Korea, experiences relatively low precipitation, with 26 mm (1.0 in) falling over just 5 days. This marks a significant decline compared to the summer months, where rainfall peaks, especially in July and August with averages of 235 mm (9.3 in) and 255 mm (10.1 in), respectively. The transition into winter brings a noticeable shift in weather patterns, as December’s precipitation is lighter than the 54 mm (2.1 in) seen in both October and November. This trend of decreasing rainfall continues from late autumn into winter, providing a brief respite from the heavy downpours of previous months, while setting the stage for the drier conditions typical of the upcoming winter season.

December Precipitation Trends in Osan

The chart displays monthly precipitation patterns in Osan, 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 Osan, December typically receives around 26 mm (1.0 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec212347549880235256136625426
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in Osan

In Osan, South Korea, December brings a noticeable shift as humidity levels begin to decline, averaging around 74%. This marks a decrease from the peak months of July and August, when humidity soared to 91%, creating a sticky summer atmosphere. Following the humidity highs of late spring and summer, November's 80% provides a transitional cushion before the winter chill sets in. As temperatures drop in December, residents can expect a more comfortable yet still humid environment, reminiscent of early spring months like March and February, both recorded at 65%. Overall, December signifies the start of drier times, paving the way for the colder months ahead.

December Average Humidity in Osan

This chart illustrates the average monthly humidity levels in Osan, 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 Osan 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 Osan

As December rolls into Osan, South Korea, residents can expect a moderate UV Index of 3, indicating a safe time for outdoor activities with a burn time of 30 minutes. This drop in UV levels signifies a shift from the extreme and very high warnings felt over the summer months, when the index peaked at 11 in July and August. As the year comes to a close, the UV exposure categories trend downwards, creating a welcoming environment for holiday festivities while reminding us to stay sun-safe. For detailed and updated UV information, check out Osan UV Index.

Maximum UV Index Levels in Osan for December

The chart shows the monthly maximum UV Index (UVI) for Osan 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 Osan typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec346891011119643
Data source: Osan 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 Osan

In Osan, South Korea, December brings a delightful dose of sunshine with around 235 hours of sunlight, making it a serene month as the year draws to a close. While it may not reach the record highs of May and June, which boast over 315 hours, December still outshines the preceding months of November, with 231 hours, and January, with just 198 hours. This trend reflects a gradual transition from the brighter mid-year months to the more subdued winter days, yet December holds its own by providing moments of warmth and light amidst the chilly air. As the year wraps up, the sunshine continues to play a vital role in brightening the shorter days, inviting residents and visitors alike to enjoy the crisp beauty of the season.

Monthly Sunshine Duration in Osan: December Highlighted

The December sunshine duration represents the total number of hours Osan 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.
JanFebMarAprMayJunJulAugSepOctNovDec198h242h283h289h315h318h293h290h261h266h231h235h
Data source: Osan December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Osan During December

As December rolls into Osan, South Korea, the likelihood of sunny weather begins to shine brighter, with a commendable 63% chance of sunshine. This marks a noticeable increase from the preceding months, with November already hovering at 57%. The trend towards sunnier days is particularly striking when considered against the backdrop of the warmer summer months, where the chances dip as low as 30% in July and 31% in August. As the year winds down, December not only promises a festive atmosphere but also encourages outdoor activities, thanks to its above-average sunshine levels compared to earlier fall months. Embrace the holiday spirit in Osan under a sky that is more likely to be filled with sunlight than clouds!

Percentage of Sunny Days in December in Osan

The chart illustrates the percentage of sunny days in Osan 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 Osan experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%53%43%43%39%40%30%31%39%47%57%63%
Data source: Osan December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Osan in December

In Osan, South Korea, December brings a familiar chill and a reduction in daylight, with only 9 hours to bask in the sun. This marks the culmination of a gradual decline that began in late autumn, when daylight steadily decreased from a peak of 14 hours in mid-summer. As the year progresses from January through November, the hours of sunlight increase, peaking in May and June before tapering off again in the colder months. By February, daylight starts its upward climb once more, hinting at the promise of longer days ahead as winter fades. This cyclical dance of daylight not only shapes the rhythm of daily life but also connects the residents of Osan to the seasonal changes, marking a transition toward sunnier times in the impending spring.

Average Daylight Hours in Osan for December

The chart illustrates the variation in daylight duration in Osan 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 48m11h 57m13h 9m14h 9m14h 40m14h 24m13h 32m12h 23m11h 12m10h 9m9h 37m
Data source: Osan daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Osan

As the calendar flips to December, the winds in Osan, South Korea, begin to breathe a little more energetically, with an average speed of 2.9 m/s (7 mph). This slight uptick is a refreshing change from the subdued breezes of the summer months, where the wind speed dipped to a gentle 2.0 m/s (4 mph) in July. Throughout the year, Osan experiences its windiest spells in January and February, but December emerges with a refreshing chill that carries the promise of winter. Interestingly, the average wind speeds fluctuate throughout the year, with a noticeable decline during the warmer months before gradually rising again as the air cools. This seasonal dance not only shapes the local climate but also adds a dynamic touch to the crisp December days.

Average December Wind Speed in Osan

The chart displays monthly wind speed patterns in Osan, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.42.72.92.92.22.02.32.72.42.72.9 m/s
Data source: Osan December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Osan Compares to Other Months

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

In December, the weather tends to be milder with average temperatures around 0°C (33°F), while January brings colder conditions, with average temperatures dropping to -2°C (29°F). Although both months can see maximum temperatures reaching as high as 13°C (55°F), January typically experiences lower minimum temperatures, plunging to as low as -17°C (2°F). Precipitation is slightly more frequent in December, occurring on five days with a total of 26 mm (1.0 in), compared to just two days in January with 21 mm (0.8 in). Humidity levels also decrease from December's 74% to January's 71%. For more detailed insights on January weather, you can visit Osan weather in January.

In December, the weather features a minimum temperature of -14°C (8°F) and an average of 0°C (33°F), with a maximum reaching 13°C (56°F). The month experiences a total precipitation of 26 mm (1.0 in) over approximately 5 days, coupled with a relatively high humidity of 74%. In contrast, February sees a slightly lower minimum temperature of -15°C (4°F), while maintaining the same average temperature of 0°C (33°F) and a higher maximum of 18°C (65°F). Precipitation is slightly reduced at 23 mm (0.9 in) over 4 days, with humidity dropping to 65%. This comparison highlights the gradual warming trend as winter progresses, making February feel more temperate than December. For more details, you can check Osan weather in February.

In December, the weather is considerably colder, with temperatures ranging from a minimum of -14°C (8°F) to a maximum of 13°C (56°F) and an average of 0°C (33°F). The month sees around 26 mm (1.0 in) of precipitation over five days, accompanied by a higher humidity level of 74%. In contrast, March experiences a more moderate climate, featuring temperatures that range from a minimum of -6°C (21°F) to a maximum of 21°C (70°F), with an average temperature of 7°C (44°F). Precipitation in March increases to 47 mm (1.9 in) over the same five days, but humidity drops to 65%. For those interested in the specifics of weather in March, more information can be found at Osan weather in March.

December and April present markedly different weather patterns. In December, temperatures can plunge to a minimum of -14°C (8°F), with an average of 0°C (33°F) and a maximum of 13°C (56°F), creating a chilly atmosphere. The month sees about 26 mm (1.0 in) of precipitation over approximately five days, with humidity levels at 74%. In contrast, April experiences milder conditions, where temperatures range from a minimum of -1°C (30°F) to a comfortable maximum of 28°C (82°F), averaging around 12°C (54°F). Precipitation increases to 54 mm (2.1 in) over the same number of days, with humidity slightly higher at 75%. This transition from the cold of December to the warmth of April is beautifully encapsulated in the changing landscape. For more details on April weather in Osan, check out Osan weather in April.

Comparing the weather in December and May reveals a striking contrast. December features much colder temperatures, with a minimum of -14°C (8°F) and an average hovering around freezing at 0°C (33°F), while May enjoys a milder climate, with temperatures ranging from a minimum of 6°C (42°F) to a maximum of 31°C (89°F). Additionally, precipitation is more common in May, totaling 98 mm (3.9 in) over about 8 days, compared to December's 26 mm (1.0 in) over 5 days. Humidity is also higher in May at 81%, compared to December’s 74%. For more detailed information, you can check Osan weather in May.

December and June present two starkly contrasting weather profiles. December experiences much colder temperatures, with an average around 0°C (33°F) and a maximum reaching only 13°C (56°F), while humidity is relatively low at 74%. In contrast, June boasts much warmer weather, featuring an average temperature of 22°C (72°F) and highs that can soar to 33°C (91°F), alongside higher humidity levels at 85%. Additionally, June sees increased precipitation at 80 mm (3.1 in) over 7 days compared to December’s 26 mm (1.0 in) over 5 days. For more detailed information, you can check Osan weather in June.

December and July present starkly contrasting weather conditions. In December, temperatures can plunge to a chilling minimum of -14°C (8°F), with an average around 0°C (33°F), and a maximum reaching 13°C (56°F). The month also sees relatively low precipitation, totaling 26 mm (1.0 in) over about 5 days, with humidity levels at 74%. In contrast, July experiences a much warmer climate with minimum temperatures around 18°C (65°F) and an average of 26°C (79°F), peaking at a sweltering 36°C (98°F). This summer month is much wetter, with a total of 235 mm (9.3 in) of rain spread across 14 days and humidity soaring to 91%. For more details, check out Osan weather in July.

December and August present strikingly contrasting weather patterns. In December, temperatures can plummet to a chilling minimum of -14°C (8°F) and hover around an average of 0°C (33°F), with a maximum reaching only 13°C (56°F). The month sees minimal precipitation, averaging 26 mm (1.0 in) over just 5 days, and humidity levels are relatively moderate at 74%. In vivid contrast, August boasts a much warmer climate, with lows of 16°C (61°F) and average highs soaring to 27°C (80°F), peaking at a sweltering 38°C (101°F). This summer month also experiences significantly higher precipitation, totaling 255 mm (10.1 in) across 14 rainy days, accompanied by elevated humidity levels at 91%. For a closer look at the conditions during this vibrant summer month, check Osan weather in August.

In December, temperatures plummet to a minimum of -14°C (8°F) with an average of 0°C (33°F) and a maximum of 13°C (56°F), creating a much colder atmosphere compared to September. During the latter month, temperatures range from a mild 9°C (48°F) to a warm 31°C (88°F), with a pleasant average of 22°C (71°F). September also sees significantly higher precipitation levels at 136 mm (5.4 in) over 9 days, compared to December's 26 mm (1.0 in) over just 5 days. Humidity remains relatively high in both months, slightly increasing from December's 74% to September's 77%. For more information on September weather in Osan, visit Osan weather in September.

December and October present contrasting weather patterns. In December, temperatures plummet with a low of -14°C (8°F) and an average of 0°C (33°F), whereas October enjoys much milder conditions, boasting a minimum of 1°C (33°F) and an average of 15°C (59°F). While both months experience precipitation on roughly five days, October sees a significantly higher total of 62 mm (2.5 in) compared to December's 26 mm (1.0 in). Additionally, humidity levels in October are slightly higher at 79%, compared to December's 74%. For more details on October's climate, you can visit Osan weather in October.

In comparing the weather of December and November, December experiences significantly colder temperatures, with a minimum of -14°C (8°F) and an average of 0°C (33°F), while November sees milder conditions with a minimum of -5°C (23°F) and an average of 8°C (46°F). Additionally, the maximum temperature in December peaks at 13°C (56°F), compared to a more comfortable high of 21°C (70°F) in November. Precipitation levels also differ; December receives 26 mm (1.0 in) of rain over five days, whereas November has a higher total of 54 mm (2.1 in) across the same number of days. Notably, November has a slightly higher humidity level of 80%, compared to December's 74%. For more details, you can visit Osan weather in November.

Compare Osan's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Osan

As December settles in, Osan transforms into a winter wonderland distinct from the milder temperatures of previous months. With an average temperature hovering around freezing, the chill sets the stage for a serene yet brisk atmosphere. This month witnesses a slight uptick in precipitation, bringing the first hints of snow, while the humidity remains relatively high, creating a unique sensation in the air. Unlike the warmer seasons, December's temperatures can plunge, reminding residents and visitors alike of winter’s bite. For those interested in understanding how Osan's December weather compares to the rest of the year, further details can be found at Osan Climate.