January in Yamaguchi averages a daily high of 9.5°C. Expect roughly 10.4 wet days totalling 69.3mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Yamaguchi is April–May.
Based on YAMAGUCHI, JA (2.4km), 1995–2024. 28 years of January data.