January in Isesaki averages a daily high of 9.2°C. Rain is rare — about 2.8 wet days and 21mm across the month. Generally workable, with some weather to plan around.
Across the year, the best time to visit Isesaki is September–November.
Based on MAEBASHI, JA (15.1km), 1995–2024. 23 years of January data.