December Weather in Karatsu, Japan

Last updated: August 21, 2025

December in Karatsu, Japan presents a cool yet captivating climate, with maximum temperatures reaching 21°C (71°F) and an average of 10°C (50°F). The month is characterized by a brisk minimum temperature of 1°C (35°F), creating a refreshing winter atmosphere. Rainfall contributes notably to the season, with a total precipitation of 81 mm (3.2 in) spread across 9 days, adding a touch of moisture to the air, which hovers around a comfortable 72% humidity. Whether you’re exploring local culture or enjoying the scenic winter landscapes, December offers a unique charm that highlights Karatsu's seasonal beauty.

December Temperature in Karatsu

As December rolls into Karatsu, Japan, temperatures begin to dip, signaling the onset of winter. With a minimum of 1°C (35°F), the month starts cooler than November, yet still boasts a comfortable average of 10°C (50°F) and a pleasant maximum of 21°C (71°F). This transition highlights a gradual cooling trend as the year ends, with December's temperatures providing a gentle reprieve from the summer heat, whilst remaining milder compared to the frigid January lows. The variation from the sizzling highs of summer to the cooler December days offers a unique charm, making it an enticing time to experience the local culture wrapped in the cozy ambiance of the season.

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

The chart illustrates December temperature patterns in Karatsu, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Karatsu, December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec464753596672798277685950
Data source: Temperature data for Karatsu 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 Karatsu

In December, Karatsu experiences a moderate level of precipitation, with 81 mm (3.2 in) falling over approximately 9 days. This amount reflects a slight decrease compared to November’s lower total of 53 mm (2.1 in), suggesting the onset of winter brings a more stable, yet wet climate. Interestingly, this trend of reduced precipitation days continues from the previous month, emphasizing a shift towards drier conditions as the year concludes. While December's rainfall is less than the summer months, it still contributes significantly to the region's overall annual totals, showcasing Karatsu's dynamic weather patterns as it transitions into the colder season.

December Precipitation Trends in Karatsu

The chart displays monthly precipitation patterns in Karatsu, 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 Karatsu, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec69841361151531913242662101125381
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Karatsu

In December, humidity in Karatsu, Japan settles at a comfortable 72%, marking a slight decrease from the preceding months. This drop is part of a broader trend observed as the year transitions from the sweltering heat of summer, where humidity peaks at a high 97% in July, to the more moderate levels of winter. The months leading up to December, particularly June and July, showcase the city's humid climate, with averages consistently above 90%. As autumn unfolds, humidity gradually recedes, providing a refreshing change before winter sets in. This seasonal ebb and flow highlights Karatsu's unique climate, where the moist summer air gives way to cooler, crisper conditions by the end of the year.

December Average Humidity in Karatsu

This chart illustrates the average monthly humidity levels in Karatsu, 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 Karatsu is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec73%69%71%79%87%92%97%94%84%79%75%72%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Karatsu

As the year draws to a close, December in Karatsu, Japan, sees a moderate UV Index of 4, indicating a lesser intensity compared to the preceding summer months. After experiencing extreme levels peaking at 12 from July through September, the UV exposure significantly drops in the final months, returning to more manageable levels with a burn time of approximately 30 minutes. This trend showcases the seasonal shift as winter approaches, where prolonged sun exposure becomes less critical. It's vital for residents and visitors alike to remain aware of these changes, ensuring skin protection during outdoor activities. For more detailed insights, visit the Karatsu UV Index.

Maximum UV Index Levels in Karatsu for December

The chart shows the monthly maximum UV Index (UVI) for Karatsu 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 Karatsu typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121211764
Data source: Karatsu 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 Karatsu

In Karatsu, Japan, December brings a gentle shift in daylight, with 212 hours of sunshine. While the month may not boast the sunniest days compared to the summer peak of 305 hours in August, it still offers a comforting glow as the year draws to a close. Following the trend of diminishing hours since May’s high, December's light lingers a bit longer than the preceding months of November (237 hours) and October (254 hours), creating a cozy atmosphere. This gradual reduction in daylight invites both locals and visitors to indulge in winter festivities, ensuring that even amidst shorter days, Karatsu's charm continues to shine brightly.

Monthly Sunshine Duration in Karatsu: December Highlighted

The December sunshine duration represents the total number of hours Karatsu 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.
JanFebMarAprMayJunJulAugSepOctNovDec178h230h262h281h293h282h283h305h257h254h237h212h
Data source: Karatsu December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Karatsu During December

In Karatsu, Japan, the likelihood of sunny weather in December stands at 37%, reflecting a slight dip as the year draws to a close. This trend marks a noticeable reduction from the sunnier months of October and November, which boast probabilities of 60% and 48%, respectively. As winter sets in, December's sunshine chances align more closely with the variability seen in early spring and late autumn. Despite this decrease, the month holds on to a moderate chance of bright days, offering a refreshing contrast to the colder climate that often prevails during the season.

Percentage of Sunny Days in December in Karatsu

The chart illustrates the percentage of sunny days in Karatsu 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 Karatsu experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec32%44%37%41%33%27%21%29%33%60%48%37%
Data source: Karatsu December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Karatsu in December

As the year comes to a close, December in Karatsu, Japan, ushers in a notable reduction in daylight, offering just 9 hours of light. This marks the lowest point of sunlight in the year, following a gradual decline from the vibrant 14 hours of daylight seen in the summer months of June and July. The transition from 11 hours in October to the shorter days of November and December illustrates a clear seasonal shift, paving the way for the longer hours of daylight that emerge as spring approaches. This rhythmic ebb and flow of daylight not only sets the tone for the winter season but also emphasizes the beauty of nature's cyclical patterns, inviting residents to appreciate the cozy charm of shorter days.

Average Daylight Hours in Karatsu for December

The chart illustrates the variation in daylight duration in Karatsu throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 11m10h 58m11h 58m13h13h 53m14h 18m14h 5m13h 20m12h 20m11h 19m10h 25m9h 57m
Data source: Karatsu daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Karatsu

In December, the wind in Karatsu, Japan picks up slightly to an average speed of 4.7 m/s (11 mph), revitalizing the cooler days of late autumn. This shift marks a notable increase from the gentle breezes of summer, where wind speeds dipped to their lowest, averaging around 2.7 m/s (6 mph) in June. As we transition from November's 4.3 m/s, the December winds signal a return to brisker conditions, reminiscent of the early winter months. Notably, the average wind speed has remained relatively consistent throughout the fall, hovering between 4.0 m/s in April and 4.7 m/s in December, maintaining a refreshing atmosphere that complements the seasonal scenery. As the year draws to a close, the invigorating December winds invite residents and visitors alike to embrace the charm of Karatsu during this picturesque time of year.

Average December Wind Speed in Karatsu

The chart displays monthly wind speed patterns in Karatsu, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.84.84.14.03.72.73.23.33.63.44.34.7 m/s
Data source: Karatsu December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Karatsu Compares to Other Months

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

In December, temperatures in the region typically range from a minimum of 1°C (35°F) to a maximum of 21°C (71°F), with an average temperature of 10°C (50°F). The month experiences 81 mm (3.2 in) of precipitation over 9 days, coupled with a humidity level of 72%. In contrast, January sees a slight drop in temperatures, with minimums around -1°C (31°F) and maximums reaching 18°C (64°F), averaging 8°C (46°F). Precipitation in January decreases to 69 mm (2.7 in), still spread over 9 days, and humidity remains similar at 73%. For more details on January weather, you can visit Karatsu weather in January.

December and February showcase a transition in weather patterns, with December tending to be slightly milder overall. December's temperatures range from a minimum of 1°C (35°F) to a maximum of 21°C (71°F), while February experiences a minimum of 0°C (31°F) and a maximum of 19°C (67°F). Both months receive comparable precipitation, with December averaging 81 mm (3.2 in) over 9 days, while February sees 84 mm (3.3 in) over 11 days. Despite the slight increase in rainfall days in February, humidity remains relatively stable, with December at 72% and February slightly lower at 69%. For more details on February weather, you can check out Karatsu weather in February.

In December, the weather features a milder temperature range with a minimum of 1°C (35°F) and a maximum of 21°C (71°F), averaging around 10°C (50°F). The month experiences moderate precipitation of 81 mm (3.2 in) over approximately 9 days, along with a humidity level of 72%. In contrast, March sees slightly warmer temperatures, with a minimum of 5°C (41°F) and a maximum of 20°C (68°F), averaging 12°C (53°F). However, it also brings more precipitation at 136 mm (5.4 in) across about 11 days, while humidity remains relatively consistent at 71%. For a detailed view of March conditions, visit Karatsu weather in March.

December and April present distinct weather patterns, reflecting the transition from winter to spring. In December, temperatures range from a chilly minimum of 1°C (35°F) to a comfortable maximum of 21°C (71°F), with an average of 10°C (50°F). The month sees a total precipitation of 81 mm (3.2 in) over 9 days and a humidity level of 72%. In contrast, April experiences milder conditions, with temperatures starting at a minimum of 7°C (45°F) and peaking at 24°C (75°F), averaging 15°C (59°F). Although April receives more rainfall, totaling 115 mm (4.5 in) across the same number of days, its humidity rises slightly to 79%. For a closer look at the weather in April, you can check Karatsu weather in April.

In December, temperatures are generally cooler, ranging from a chilly minimum of 1°C (35°F) to a comfortable maximum of 21°C (71°F), with an average of 10°C (50°F). The month sees around 81 mm (3.2 inches) of precipitation spread over 9 days, accompanied by a humidity level of 72%. In contrast, May experiences much milder conditions, with temperatures starting at a minimum of 11°C (53°F) and peaking at 27°C (80°F), averaging 19°C (67°F). However, this month receives more rain, totaling 153 mm (6.0 inches) across 11 days and higher humidity at 87%. For further details on weather patterns, you can visit Karatsu weather in May.

The weather in December presents a cooler and more moderate climate, with temperatures ranging from a minimum of 1°C (35°F) to a maximum of 21°C (71°F) and an average of 10°C (50°F). Additionally, December experiences around 81 mm (3.2 in) of precipitation over approximately 9 days, alongside a humidity level of 72%. In contrast, June boasts much warmer temperatures, with a minimum of 17°C (63°F), an average of 22°C (73°F), and a maximum of 29°C (84°F). June is also wetter, receiving 191 mm (7.5 in) of rainfall over 13 days, and has higher humidity at 91%. For more specific details about the weather in June, you can visit Karatsu weather in June.

December and July present starkly contrasting weather conditions. In December, temperatures range from a cool 1°C (35°F) at night to a mild average of 10°C (50°F) during the day, with highs reaching up to 21°C (71°F). The month experiences about 81 mm (3.2 in) of precipitation over roughly 9 days, accompanied by a humidity level of 72%. Conversely, July is much warmer, with nighttime lows of 20°C (68°F) and daytime averages peaking at 26°C (79°F), hitting highs around 33°C (91°F). Rainfall is significantly higher in July, totaling 323 mm (12.7 in) spread over 18 days, along with humidity levels soaring to 97%. For more details on the specific weather in July, you can visit Karatsu weather in July.

December and August exhibit stark contrasts in weather patterns. In December, temperatures range from a minimum of 1°C (35°F) to a maximum of 21°C (71°F), with an average of 10°C (50°F). The month sees about 81 mm (3.2 in) of precipitation over 9 days, coupled with a humidity level of 72%. In contrast, August experiences much warmer temperatures, with a minimum of 21°C (70°F), an average of 28°C (83°F), and a maximum reaching 33°C (92°F). This month is also notably wetter, with a total of 266 mm (10.5 in) of rainfall spread across 13 days, and humidity levels soaring to 94%. For more details on August weather, you can check Karatsu weather in August.

In December, the weather is considerably cooler, with temperatures ranging from a minimum of 1°C (35°F) to an average of 10°C (50°F) and a maximum of 21°C (71°F). Precipitation is relatively moderate, totaling 81 mm (3.2 in) over 9 days, with humidity around 72%. In contrast, September boasts much warmer temperatures, with a minimum of 19°C (66°F), an average of 25°C (77°F), and a maximum reaching 32°C (91°F). However, it is also wetter in September, receiving 210 mm (8.3 in) of rain across 16 days and a higher humidity level of 84%. For more detailed information, you can check Karatsu weather in September.

In comparing the weather between October and December, December tends to be significantly cooler, with temperatures ranging from a minimum of 1°C (35°F) to a maximum of 21°C (71°F), compared to October's milder range of 13°C (56°F) to 29°C (84°F). Although December has lower average temperatures, it experiences slightly less precipitation, totaling 81 mm (3.2 in) over 9 days, in contrast to October's 112 mm (4.4 in) over 10 days. Additionally, humidity levels remain relatively high in both months, with December at 72% and October at 79%. For more specific information about the weather conditions in October, you can visit Karatsu weather in October.

In comparing the weather between November and December, December tends to be cooler, with average temperatures ranging from a minimum of 1°C (35°F) to a maximum of 21°C (71°F), while November boasts milder averages between 7°C (45°F) and 23°C (74°F). Additionally, December experiences more precipitation, totaling 81 mm (3.2 in) over 9 days, compared to November's 53 mm (2.1 in) over 7 days. Humidity levels remain relatively similar, with December at 72% and November at 75%. For more details on November weather, you can visit Karatsu weather in November.

Compare Karatsu's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Karatsu

As December settles in Karatsu, the city experiences a noticeable shift in weather compared to the warmer months. With an average temperature of around 10°C (50°F), the cooler air commands cozy jackets and warm beverages, contrasting sharply with the summer heat. While rainfall persists, bringing about 81 mm (3.2 in) spread across 9 days, the humidity remains at a comfortable 72%, adding a slight chill to the atmosphere. This month invites residents and visitors alike to relish the serene beauty of Karatsu under a cool, often misty sky. For more insights into the region's climate trends, explore Karatsu Climate.