January Weather in Iwase, Japan

Last updated: August 23, 2025

In January, the average temperature in Iwase, Japan hovers around 4°C (39°F). Expect chilly nights with minimum temperatures dropping to -10°C (14°F), while daytime highs can reach up to 17°C (63°F). With an average precipitation of 38 mm (1.5 in) over 4 days, and a notably high average humidity of 88%, prepare for a damp and cool atmosphere during your stay.

January Temperature in Iwase

In January in Iwase, the average temperature is 4°C (39°F), with maximums reaching 17°C (63°F) and minimums dropping as low as -10°C (14°F). Travelers should prepare for a range of temperatures and dress in layers to ensure comfort during their visit.

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

The chart illustrates January temperature patterns in Iwase, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iwase, January typically has an average temperature of 4°C (39°F), with highs reaching up to 17°C (63°F) and lows dropping to around -10°C (14°F).

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

January Precipitation in Iwase

In Iwase in January, the total precipitation amount is 38 mm (1.5 in) spread over the course of 4 days.

January Precipitation Trends in Iwase

The chart displays monthly precipitation patterns in Iwase, 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 Iwase, January typically receives around 38 mm (1.5 inches) of precipitation spread over approximately 4 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 Iwase

In Iwase in January, humidity is 88%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making travel uncomfortable and necessitating extra layers to stay warm.

January Average Humidity in Iwase

This chart illustrates the average monthly humidity levels in Iwase, 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 Iwase is approximately 88%, 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 Iwase

In Iwase in January, 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 Iwase, you can check the information here.

Maximum UV Index Levels in Iwase for January

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

Data source: Iwase 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 Iwase Compares to Other Months

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

This table compares monthly weather conditions in Iwase, showing how January’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 (42°F)	37 mm (1.5 inches)	86%	moderate
March Weather	9°C (49°F)	124 mm (4.9 inches)	81%	high
April Weather	14°C (57°F)	112 mm (4.4 inches)	78%	very high
May Weather	19°C (67°F)	123 mm (4.8 inches)	81%	very high
June Weather	22°C (72°F)	132 mm (5.2 inches)	88%	very high
July Weather	26°C (79°F)	218 mm (8.6 inches)	92%	extreme
August Weather	28°C (82°F)	114 mm (4.5 inches)	92%	very high
September Weather	23°C (74°F)	157 mm (6.2 inches)	89%	very high
October Weather	18°C (64°F)	225 mm (8.8 inches)	87%	high
November Weather	12°C (54°F)	63 mm (2.5 inches)	85%	moderate
December Weather	6°C (43°F)	50 mm (1.9 inches)	86%	moderate