January Weather in Iruma, Japan

Last updated: August 23, 2025

In January, the average temperature in Iruma, Japan hovers around 3°C (37°F). Expect a chilly minimum of -13°C (9°F) and a pleasant maximum of 17°C (63°F). With an average precipitation of 53 mm (2.1 in) over approximately 7 days, you might want to keep an umbrella handy. Additionally, the air will feel quite humid, with an average humidity of 76%.

January Temperature in Iruma

In January in Iruma, the average temperature is 3°C (37°F). Maximums can reach 17°C (63°F), while minimums can be as low as -13°C (9°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

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

The chart illustrates January temperature patterns in Iruma, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iruma, January typically has an average temperature of 3°C (37°F), with highs reaching up to 17°C (63°F) and lows dropping to around -13°C (9°F).

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

January Precipitation in Iruma

In Iruma in January, the total precipitation amount is 53 mm (2.1 in) spread over a period of 7 days.

January Precipitation Trends in Iruma

The chart displays monthly precipitation patterns in Iruma, 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 Iruma, January typically receives around 53 mm (2.1 inches) of precipitation spread over approximately 7 days.

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

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Millimeters (mm) Inches (in)

January Humidity in Iruma

In Iruma in January, humidity is 76%. With an average temperature of 3°C (37°F), this humidity feels like trudging through a cold, damp fog that envelops you, making travel feel heavy and uncomfortable.

January Average Humidity in Iruma

This chart illustrates the average monthly humidity levels in Iruma, 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 Iruma is approximately 76%, 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 Iruma

In Iruma 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 Iruma for better planning.

Maximum UV Index Levels in Iruma for January

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

Data source: Iruma 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 Iruma Compares to Other Months

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

This table compares monthly weather conditions in Iruma, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	3°C (37°F)	53 mm (2.1 inches)	76%	moderate
February Weather	4°C (40°F)	62 mm (2.4 inches)	74%	high
March Weather	8°C (47°F)	166 mm (6.5 inches)	70%	very high
April Weather	12°C (54°F)	150 mm (5.9 inches)	74%	very high
May Weather	17°C (64°F)	148 mm (5.8 inches)	81%	extreme
June Weather	20°C (69°F)	209 mm (8.2 inches)	88%	extreme
July Weather	24°C (76°F)	312 mm (12.3 inches)	93%	extreme
August Weather	26°C (79°F)	195 mm (7.7 inches)	90%	extreme
September Weather	22°C (71°F)	247 mm (9.7 inches)	86%	very high
October Weather	16°C (61°F)	346 mm (13.6 inches)	83%	high
November Weather	11°C (52°F)	72 mm (2.8 inches)	80%	moderate
December Weather	5°C (42°F)	62 mm (2.4 inches)	78%	moderate