December Weather in Omachi, Japan

Last updated: August 23, 2025

In December, the average temperature in Omachi, Japan hovers around -5°C (24°F). Expect chilly conditions, with minimums plunging to -16°C (3°F) and maximums reaching a mild 13°C (56°F). Prepare for 206 mm (8.1 in) of precipitation spread across 22 days, and brace yourself for an average humidity of 86%—making it a truly brisk month!

December Temperature in Omachi

In December in Omachi, the average temperature is -5°C (24°F). Maximums can reach 13°C (56°F), while minimums can drop as low as -16°C (3°F). Travelers should prepare for a wide temperature range and pack accordingly.

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

The chart illustrates December temperature patterns in Omachi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Omachi, December typically has an average temperature of -5°C (24°F), with highs reaching up to 13°C (56°F) and lows dropping to around -16°C (3°F).

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

December Precipitation in Omachi

In Omachi in December, the precipitation amount is 206 mm (8.1 in) over the course of 22 days.

December Precipitation Trends in Omachi

The chart displays monthly precipitation patterns in Omachi, 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 Omachi, December typically receives around 206 mm (8.1 inches) of precipitation spread over approximately 22 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 Omachi

In Omachi in December, humidity is 86%. With an average temperature of -5°C (24°F), this humidity feels like a damp chill that seeps into your bones, making traveling uncomfortable as even the slightest breeze becomes biting, and your clothing clings uncomfortably to your skin.

December Average Humidity in Omachi

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

In Omachi in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Omachi for better planning.

Maximum UV Index Levels in Omachi for December

The chart shows the monthly maximum UV Index (UVI) for Omachi 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 Omachi typically reaches 4, which falls under the moderate exposure category.

Data source: Omachi 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 Omachi Compares to Other Months

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

This table compares monthly weather conditions in Omachi, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-8°C (19°F)	193 mm (7.6 inches)	88%	moderate
February Weather	-7°C (20°F)	181 mm (7.1 inches)	86%	high
March Weather	-1°C (30°F)	198 mm (7.8 inches)	81%	very high
April Weather	4°C (39°F)	226 mm (8.9 inches)	78%	very high
May Weather	11°C (52°F)	276 mm (10.9 inches)	81%	extreme
June Weather	15°C (59°F)	310 mm (12.2 inches)	88%	extreme
July Weather	19°C (67°F)	565 mm (22.3 inches)	92%	extreme
August Weather	20°C (69°F)	400 mm (15.8 inches)	92%	extreme
September Weather	16°C (61°F)	334 mm (13.1 inches)	89%	very high
October Weather	10°C (50°F)	284 mm (11.2 inches)	87%	high
November Weather	3°C (37°F)	139 mm (5.5 inches)	85%	moderate
December Weather	-5°C (24°F)	206 mm (8.1 inches)	86%	moderate