January Weather in Isa, Japan

Last updated: August 23, 2025

In Isa, Japan, the average temperature in January hovers around 7°C (45°F). Conditions can vary significantly, with minima dipping to -3°C (26°F) and maxima soaring to 20°C (69°F). Expect about 61 mm (2.4 in) of precipitation over approximately 7 days, accompanied by an average humidity level of 72%.

January Temperature in Isa

In January in Isa, the average temperature is 7°C (45°F). Maximums can reach 20°C (69°F), and minimums can be as low as -3°C (26°F). This variability makes it essential for travelers to pack layers to ensure comfort during their visit.

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

The chart illustrates January temperature patterns in Isa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Isa, January typically has an average temperature of 7°C (45°F), with highs reaching up to 20°C (69°F) and lows dropping to around -3°C (26°F).

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

January Precipitation in Isa

In Isa in January, the precipitation amount is 61 mm (2.4 in) over the course of 7 days.

January Precipitation Trends in Isa

The chart displays monthly precipitation patterns in Isa, 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 Isa, January typically receives around 61 mm (2.4 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 Isa

In Isa in January humidity is 72%. With an average temperature of 7°C (45°F), this humidity feels like a chilling dampness that permeates your clothing, making outdoor activities a bit uncomfortable and necessitating extra layers to stay warm.

January Average Humidity in Isa

This chart illustrates the average monthly humidity levels in Isa, 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 Isa is approximately 72%, 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 Isa

In Isa in January, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Isa.

Maximum UV Index Levels in Isa for January

The chart shows the monthly maximum UV Index (UVI) for Isa 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 Isa typically reaches 5, which falls under the moderate exposure category.

Data source: Isa 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 Isa Compares to Other Months

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

This table compares monthly weather conditions in Isa, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (45°F)	61 mm (2.4 inches)	72%	moderate
February Weather	8°C (47°F)	110 mm (4.3 inches)	68%	high
March Weather	12°C (54°F)	162 mm (6.4 inches)	72%	very high
April Weather	16°C (61°F)	159 mm (6.3 inches)	79%	extreme
May Weather	20°C (68°F)	261 mm (10.3 inches)	83%	extreme
June Weather	23°C (74°F)	386 mm (15.2 inches)	86%	extreme
July Weather	26°C (80°F)	483 mm (19.0 inches)	90%	extreme
August Weather	28°C (82°F)	234 mm (9.2 inches)	85%	extreme
September Weather	25°C (77°F)	259 mm (10.2 inches)	80%	extreme
October Weather	20°C (69°F)	141 mm (5.6 inches)	78%	very high
November Weather	14°C (57°F)	102 mm (4.0 inches)	76%	high
December Weather	9°C (48°F)	94 mm (3.7 inches)	74%	moderate