December in Ōmihachiman averages a daily high of 10.1°C. Expect roughly 14.9 wet days totalling 110.4mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Ōmihachiman is May–June.
Based on HIKONE, JA (22.1km), 1995–2024. 25 years of December data.