December in Jōetsu averages a daily high of 9.7°C. Expect roughly 23.7 wet days totalling 498.5mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Jōetsu is May–June.
Based on TAKADA, JA (5.5km), 1995–2024. 24 years of December data.