December Weather in Iyo, Japan

Last updated: August 23, 2025

In December, the average temperature in Iyo, Japan hovers around 8°C (46°F), with a minimum dipping to -1°C (31°F) and a comfortable maximum of 22°C (71°F). Expect about 69 mm (2.7 in) of precipitation spread over 10 days, contributing to an average humidity level of 77%. Stay prepared for a mix of weather this month!

December Temperature in Iyo

In December in Iyo, the average temperature is 8°C (46°F). The maximum can reach 22°C (71°F), while the minimum can drop as low as -1°C (31°F). Be prepared for a range of temperatures to ensure a comfortable and enjoyable trip.

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

The chart illustrates December temperature patterns in Iyo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iyo, December typically has an average temperature of 8°C (46°F), with highs reaching up to 22°C (71°F) and lows dropping to around -1°C (31°F).

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

December Precipitation in Iyo

In Iyo in December, the precipitation amount is 69 mm (2.7 in) spread over a period of 10 days.

December Precipitation Trends in Iyo

The chart displays monthly precipitation patterns in Iyo, 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 Iyo, December typically receives around 69 mm (2.7 inches) of precipitation spread over approximately 10 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 Iyo

In Iyo in December humidity is 77%. With an average temperature of 8°C (46°F), this humidity feels like a damp chill wrapping around you, making outdoor activities less inviting and requiring extra layers to stay comfortable while exploring.

December Average Humidity in Iyo

This chart illustrates the average monthly humidity levels in Iyo, 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 Iyo is approximately 77%, 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 Iyo

In Iyo 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 Iyo for better planning.

Maximum UV Index Levels in Iyo for December

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

Data source: Iyo 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 Iyo Compares to Other Months

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

This table compares monthly weather conditions in Iyo, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	5°C (42°F)	60 mm (2.4 inches)	74%	moderate
February Weather	6°C (43°F)	90 mm (3.6 inches)	70%	high
March Weather	10°C (50°F)	129 mm (5.1 inches)	70%	very high
April Weather	14°C (57°F)	135 mm (5.3 inches)	76%	very high
May Weather	18°C (65°F)	153 mm (6.0 inches)	82%	extreme
June Weather	22°C (72°F)	215 mm (8.5 inches)	86%	extreme
July Weather	26°C (79°F)	374 mm (14.7 inches)	91%	extreme
August Weather	27°C (81°F)	197 mm (7.7 inches)	88%	extreme
September Weather	24°C (75°F)	212 mm (8.4 inches)	85%	extreme
October Weather	19°C (66°F)	204 mm (8.0 inches)	82%	very high
November Weather	13°C (55°F)	61 mm (2.4 inches)	79%	high
December Weather	8°C (46°F)	69 mm (2.7 inches)	77%	moderate