Weather Forecast Japan January 2025. You can expect about 3 to 8 days of rain in japan during the month of january. The weather in japan in january is very cold with temperatures between 2 ° c and 9 ° c, warm clothes are a must.

Insights into temperature, precipitation, and weather trends. In osaka, japan, in january, during 5.6 rainfall days, 45mm (1.77) of precipitation is typically accumulated.