December in Kuroiso averages a daily high of 7.7°C. Expect roughly 7.3 wet days totalling 52.6mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Kuroiso is May–June.
Based on SHIRAKAWA, JA (23.7km), 1995–2024. 29 years of December data.