December Weather in Oyama, Japan

Last updated: August 23, 2025

In Oyama, Japan, the average temperature in December hovers around 6°C (43°F). You'll experience a chill, with minimums dipping to -4°C (26°F), while highs can reach a cozy 20°C (67°F). Expect about 50 mm (2.0 in) of precipitation spread over 6 days, contributing to an average humidity of 86%. Be prepared for changeable weather as you explore this beautiful locale!

December Temperature in Oyama

In December in Oyama, the average temperature is 6°C (43°F). Maximum temperatures can reach 20°C (67°F), while minimums can drop as low as -4°C (26°F). It's a great time to experience the crisp air and enjoy outdoor activities, so be sure to pack layers for your travels!

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

The chart illustrates December temperature patterns in Oyama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Oyama, December typically has an average temperature of 6°C (43°F), with highs reaching up to 20°C (67°F) and lows dropping to around -4°C (26°F).

Data source: Temperature data for Oyama generated using information from the Copernicus Climate Change Service.

December Precipitation in Oyama

In Oyama in December, the precipitation amount is 50 mm (2.0 in) over the course of 6 days.

December Precipitation Trends in Oyama

The chart displays monthly precipitation patterns in Oyama, 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 Oyama, December typically receives around 50 mm (2.0 inches) of precipitation spread over approximately 6 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Oyama

In Oyama in December humidity is 86%. With an average temperature of 6°C (43°F), this humidity feels like a chilling blanket enveloping you, making outdoor exploration feel damp and uncomfortable.

December Average Humidity in Oyama

This chart illustrates the average monthly humidity levels in Oyama, 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 Oyama is approximately 86%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Oyama

In Oyama in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Oyama, you can check the information here.

Maximum UV Index Levels in Oyama for December

The chart shows the monthly maximum UV Index (UVI) for Oyama 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 Oyama typically reaches 3, which falls under the moderate exposure category.

Data source: Oyama 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.

How December Weather in Oyama Compares to Other Months

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

This table compares monthly weather conditions in Oyama, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	4°C (39°F)	38 mm (1.5 inches)	88%	moderate
February Weather	5°C (41°F)	41 mm (1.6 inches)	86%	moderate
March Weather	9°C (49°F)	131 mm (5.2 inches)	81%	high
April Weather	14°C (57°F)	129 mm (5.1 inches)	78%	very high
May Weather	19°C (66°F)	137 mm (5.4 inches)	81%	very high
June Weather	22°C (72°F)	160 mm (6.3 inches)	88%	extreme
July Weather	26°C (78°F)	258 mm (10.2 inches)	92%	extreme
August Weather	27°C (82°F)	156 mm (6.1 inches)	92%	very high
September Weather	23°C (74°F)	195 mm (7.7 inches)	89%	very high
October Weather	18°C (64°F)	258 mm (10.1 inches)	87%	high
November Weather	12°C (53°F)	67 mm (2.6 inches)	85%	moderate
December Weather	6°C (43°F)	50 mm (2.0 inches)	86%	moderate