January Weather in Iyo, Japan

Last updated: August 23, 2025

In January, the average temperature in Iyo, Japan hovers around 5°C (or 42°F). Expect a chilly range, with minimums dipping to a brisk -4°C (25°F) and maximums reaching a mild 15°C (59°F). During this month, anticipate 60 mm (2.4 in) of precipitation spread over about 9 days, contributing to an average humidity of 74%.

January Temperature in Iyo

In January in Iyo, the average temperature is 5°C (42°F). Maximums can reach 15°C (59°F) and minimums can be as low as -4°C (25°F). Be sure to pack layers to stay comfortable during your travels!

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

The chart illustrates January 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, January typically has an average temperature of 5°C (42°F), with highs reaching up to 15°C (59°F) and lows dropping to around -4°C (25°F).

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

January Precipitation in Iyo

In Iyo in January, the total precipitation amount is 60 mm (2.4 in), occurring over a span of 9 days.

January Precipitation Trends in Iyo

The chart displays monthly precipitation patterns in Iyo, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Iyo, January typically receives around 60 mm (2.4 inches) of precipitation spread over approximately 9 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Iyo

In Iyo in January, humidity is 74%. With an average temperature of 5°C (42°F), this humidity feels like a damp chill that penetrates your clothes, making outdoor activities somewhat uncomfortable and necessitating extra layers to keep warm while exploring.

January Average Humidity in Iyo

This chart illustrates the average monthly humidity levels in Iyo, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Iyo is approximately 74%, offering insight into how humid the weather typically is during this month.

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

January UV Index in Iyo

In Iyo in January, 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 January

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

Data source: Iyo January 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 January 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 January’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 January’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