December Weather in Hayama, Japan

Last updated: August 21, 2025

In Hayama, Japan, December presents a cool and somewhat damp climate, with average temperatures hovering around 11°C (52°F). The maximum temperature can reach a mild 21°C (69°F), while nighttime lows dip to a chilly 3°C (37°F). Rainfall is fairly common, accumulating to 82 mm (3.2 in) over the month across 11 days, contributing to a humidity level of 78%. Visitors can expect a blend of crisp air and occasional rain, making it an ideal time for cozy indoor activities or refreshing coastal strolls.

December Temperature in Hayama

In December, Hayama, Japan, begins to embrace the chill of winter, with temperatures ranging from a minimum of 3°C (37°F) to a comfortable maximum of 21°C (69°F). The average temperature sits at around 11°C (52°F), marking a notable drop from the milder conditions of November. This transitional month often sees the warmth of autumn give way to crisper air, while still offering afternoons that can be pleasantly mild. As the year draws to a close, the climate invites cozy sweaters and warm beverages, setting the perfect scene for festive celebrations in this scenic coastal town.

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

The chart illustrates December temperature patterns in Hayama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hayama, 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).
JanFebMarAprMayJunJulAugSepOctNovDec464752576570768075676051
Data source: Temperature data for Hayama 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 Hayama

December in Hayama, Japan, sees a moderate precipitation level of 82 mm (3.2 in), which is a notable dip compared to the previous months. This month typically experiences about 11 days of rainfall, maintaining a consistent trend of relatively frequent precipitation. While December’s rainfall is less than in the preceding months, it effectively contributes to the overall wetness of the fall season, which peaks in October at 303 mm (11.9 in). As the year winds down, the decreasing precipitation indicates a shift towards the drier winter months. Despite the reduction, December remains critical for sustaining the region's lush landscapes, just as the earlier wetter months have ensured a rich tapestry of greenery.

December Precipitation Trends in Hayama

The chart displays monthly precipitation patterns in Hayama, 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 Hayama, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec646217214114819722612920830311182
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Hayama

In Hayama, Japan, December brings a noticeable shift in humidity levels, averaging 78%. This reflects a moderate decrease from the peak of 93% experienced in the sweltering summer months of July and August. As autumn fades, humidity levels begin to decline gradually, from 80% in November, hinting at the crispness of winter ahead. December's figures, however, still show substantial moisture in the air compared to the drier spring months, emphasizing Hayama's stable, humid climate year-round. The trend of higher humidity during the summer transitioning to milder levels in winter makes December a unique blend of lingering warmth and the anticipation of colder weather.

December Average Humidity in Hayama

This chart illustrates the average monthly humidity levels in Hayama, 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 Hayama is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%74%70%74%82%88%93%90%86%83%80%78%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Hayama

December in Hayama, Japan, sees a moderate UV Index of 4, allowing for approximately 30 minutes of sun exposure before the risk of skin damage increases. This month marks a shift from the extreme levels experienced during the summer, where values soared to 11, requiring only 10 minutes of exposure for potential burn. As winter approaches, the UV Index trends downward, reflecting shorter days and lower UV radiation. However, it’s important to remain vigilant, as even moderate levels can lead to sunburn with prolonged sun exposure. For a detailed overview of sun safety in Hayama, visit Hayama UV Index.

Maximum UV Index Levels in Hayama for December

The chart shows the monthly maximum UV Index (UVI) for Hayama 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 Hayama typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec458101111111110754
Data source: Hayama 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 Hayama

December in Hayama, Japan, offers a delightful continuation of the autumn sunshine, with 226 hours of daylight. This marks a consistent trend from November, which also recorded the same amount of sun, enriching the landscape with warm hues and a cozy atmosphere. As the year draws to a close, the sunlight slowly starts to decline from the summer peak in August, which boasts an impressive 297 hours. However, December remains bright, contributing to a beautiful transition into the winter months. Overall, while daylight hours are waning, the charm of Hayama shines through, making December a delightful month for outdoor activities and scenic strolls along the coast.

Monthly Sunshine Duration in Hayama: December Highlighted

The December sunshine duration represents the total number of hours Hayama 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.
JanFebMarAprMayJunJulAugSepOctNovDec187h224h255h269h286h262h249h297h239h205h226h226h
Data source: Hayama December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hayama During December

In Hayama, Japan, December offers a notable shift in weather patterns, boasting a 67% chance of sunny days. This marked increase from the preceding months aligns with the trend of higher sunshine probabilities that emerge as the year wraps up. Notably, December surpasses November's already respectable 62%, positioning it among the sunniest months of winter. Following the trend of early winter, December's weather delights with promising opportunities for outdoor activities, making it an ideal time to soak in the sun before the year concludes. As the year transitions toward its finale, the likelihood of enjoying clear, sunny skies enhances the charm of this coastal town.

Percentage of Sunny Days in December in Hayama

The chart illustrates the percentage of sunny days in Hayama 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 Hayama experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec53%64%41%49%24%25%35%38%29%48%62%67%
Data source: Hayama December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hayama in December

In Hayama, Japan, the daylight duration exhibits a fascinating seasonal rhythm throughout the year. From January to November, daylight gradually increases, peaking in May and June with 14 hours of bright sunshine. As summer transitions into autumn, the daylight begins to wane, with September still enjoying a generous 12 hours before tapering off. By December, the days are noticeably shorter, with only 9 hours of daylight, signaling the onset of winter. This clear pattern highlights the dynamic shift from ample summer light to the cozy, darker days of winter, inviting residents and visitors alike to embrace the beauty of each season.

Average Daylight Hours in Hayama for December

The chart illustrates the variation in daylight duration in Hayama throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 3m10h 53m11h 58m13h 4m14h 1m14h 29m14h 15m13h 26m12h 22m11h 16m10h 18m9h 48m
Data source: Hayama daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Hayama

As December settles over Hayama, Japan, the coastal town experiences a refreshing average wind speed of 5.4 m/s (12 mph), maintaining consistency with the winds felt in the previous months. Notably, December's breezes reflect a gradual shift from the lighter summer winds of 3.3 m/s (7 mph) in July and 3.7 m/s (8 mph) in June, ramping up as the year draws to a close. The winter months typically see a slight uptick, as temperatures drop and festive cheer fills the air, leading to invigorating gusts that are emblematic of the season. This gentle yet brisk wind serves as a reminder of nature's persistent rhythm, making December an ideal time for seaside strolls along Hayama's picturesque shores.

Average December Wind Speed in Hayama

The chart displays monthly wind speed patterns in Hayama, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.35.85.45.25.33.73.35.05.25.45.35.4 m/s
Data source: Hayama December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Hayama Compares to Other Months

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

December and January exhibit distinct weather patterns, reflecting the transition between the end of the year and the start of a new one. In December, temperatures range from a minimum of 3°C (37°F) to a maximum of 21°C (69°F), with an average of 11°C (52°F). The month experiences 82 mm (3.2 in) of precipitation over 11 days, contributing to a relatively high humidity level of 78%. In contrast, January tends to be cooler, with temperatures dropping to a minimum of 1°C (34°F) and reaching a maximum of 18°C (64°F), resulting in an average temperature of 8°C (47°F). Precipitation decreases to 64 mm (2.5 in) over just 6 days, accompanied by a slightly lower humidity level of 76%. For more detailed information on January weather, you can check Hayama weather in January.

In December, temperatures range from a minimum of 3°C (37°F) to a maximum of 21°C (69°F), with an average of 11°C (52°F). The month experiences higher precipitation levels at 82 mm (3.2 in) over 11 days, contributing to a humidity level of 78%. In contrast, February sees slightly cooler temperatures, with a minimum of 2°C (36°F) and a maximum of 17°C (63°F), resulting in an average of 8°C (47°F). Precipitation is also lower at 62 mm (2.4 in) over just 8 days, and humidity drops to 74%. For more detailed insights into February's climate, visit Hayama weather in February.

In December, the weather features mild temperatures with a minimum of 3°C (37°F), an average of 11°C (52°F), and a maximum of 21°C (69°F). The month experiences moderate precipitation of 82 mm (3.2 in) over 11 days, coupled with a relatively high humidity level of 78%.

In contrast, March sees similar minimum temperatures (3°C or 38°F) and an identical average temperature of 11°C (52°F), but the maximum temperature drops slightly to 19°C (66°F). This month also experiences increased precipitation, totaling 172 mm (6.8 in) spread across 12 days, while humidity lowers to 70%. For more detailed information, you can check Hayama weather in March.

Overall, while December offers slightly warmer maximum temperatures and higher humidity, March brings increased rainfall but slightly cooler daytime weather.

In December, the weather is generally cooler, with average temperatures ranging from a minimum of 3°C (37°F) to a maximum of 21°C (69°F), while April sees a slight increase in warmth, with temperatures starting at a minimum of 6°C (43°F) and peaking at 21°C (70°F). Precipitation levels also differ, with December experiencing 82 mm (3.2 in) of rain over 11 days, compared to April's higher total of 141 mm (5.5 in) across 12 days. Although April has more precipitation, the humidity level is slightly lower at 74%, in contrast to December’s 78% humidity. For a more detailed look into April weather conditions, check out Hayama weather in April.

In December, temperatures are generally cooler with a minimum of 3°C (37°F), averaging around 11°C (52°F) and peaking at a maximum of 21°C (69°F). The month experiences 82 mm (3.2 inches) of precipitation over 11 days, combined with a humidity level of 78%. In contrast, May brings warmer weather, with minimum temperatures rising to 12°C (54°F), an average of 18°C (65°F), and a maximum of 23°C (74°F). Precipitation increases to 148 mm (5.8 inches), also spread over 11 days, while humidity slightly rises to 81%. For a more detailed look at weather patterns in May, visit Hayama weather in May.

December and June present quite contrasting weather conditions. In December, temperatures range from a cool minimum of 3°C (37°F) to a pleasant maximum of 21°C (69°F), with an average of 11°C (52°F). The month sees moderate precipitation of 82 mm (3.2 in) over about 11 days, coupled with a humidity level of 78%. In stark contrast, June experiences warmer temperatures, with a minimum of 16°C (62°F) and a maximum of 26°C (79°F), averaging around 21°C (70°F). Additionally, it is a wetter month, recording 197 mm (7.8 in) of rainfall across 13 days, alongside a higher humidity level of 88%. For more insights into June conditions, you can visit Hayama weather in June.

December and July present starkly contrasting weather conditions. In December, temperatures range from a minimum of 3°C (37°F) to a maximum of 21°C (69°F), with an average of 11°C (52°F). The month sees about 82 mm (3.2 in) of precipitation spread over 11 days, accompanied by a humidity level of 78%. In contrast, July is significantly warmer, with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 28°C (83°F), and an average of 25°C (77°F). This summer month experiences much higher precipitation, totaling 226 mm (8.9 in) over 17 days, while humidity levels rise to 93%. For more detailed insights, check out Hayama weather in July.

In December, the weather is significantly cooler, with average temperatures ranging from a minimum of 3°C (37°F) to a maximum of 21°C (69°F). The month experiences about 82 mm (3.2 in) of precipitation over 11 days, along with a relatively high humidity level of 78%. In contrast, August brings much warmer conditions, with minimum temperatures starting at 21°C (70°F) and reaching up to 31°C (87°F) on average. Precipitation in August is greater at 129 mm (5.1 in) over 12 days, and the humidity climbs to 90%, creating a more muggy atmosphere. For more specific information on August weather, you can visit Hayama weather in August.

In comparing the weather of December and September, significant differences emerge. December experiences cooler temperatures, ranging from a minimum of 3°C (37°F) to a maximum of 21°C (69°F), with an average of 11°C (52°F), while September is much warmer, with temperatures peaking at 29°C (84°F) and averaging 24°C (75°F). Precipitation also contrasts notably; December sees 82 mm (3.2 in) of rain over 11 days, whereas September is considerably wetter, with 208 mm (8.2 in) over 17 days. Additionally, humidity levels are slightly higher in September at 86% compared to December's 78%. For a closer look at September's weather details, you can visit Hayama weather in September.

In comparing the weather of December and October, one can observe distinct differences in temperature and precipitation patterns. December shows a mild temperature range with a minimum of 3°C (37°F) and an average of 11°C (52°F), while October is considerably warmer, featuring a minimum temperature of 13°C (56°F) and an average of 20°C (68°F). Precipitation levels also vary significantly; December experiences 82 mm (3.2 in) over 11 days, whereas October sees a much higher total of 303 mm (11.9 in) across 17 days. Additionally, December's humidity sits at 78%, slightly lower than October's 83%. For more details about October weather specifically, you can visit Hayama weather in October.

In comparing the weather of December with November, December tends to be slightly cooler, with minimum temperatures dropping to 3°C (37°F) compared to November’s minimum of 6°C (43°F). The average temperature in December is lower at 11°C (52°F), while November maintains a warmer average of 15°C (60°F). Both months experience similar maximum temperatures, peaking at 21°C (69°F) in December and 21°C (71°F) in November. Precipitation is more intense in November, with 111 mm (4.4 in) over 12 days, compared to December's 82 mm (3.2 in) over 11 days. Humidity levels remain relatively high in both months, with December at 78% and November slightly higher at 80%. For a more detailed look at November's weather, you can visit Hayama weather in November.

Compare Hayama's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Hayama

December in Hayama ushers in a notable transition from the milder months, bringing cooler temperatures and a hint of winter. With an average chill settling around 11°C (52°F), December stands out from the warmer autumn months, while the maximum daytime warmth of 21°C (69°F) offers a brief respite from the cold. This month also experiences a significant uptick in precipitation, with rain gracing the area on nearly half the days. The higher humidity levels contribute to a distinct atmosphere, making December a unique blend of coolness and moisture compared to the preceding seasons. For a more comprehensive look at the climate nuances throughout the year, check out Hayama Climate.