December in Yamatokōriyama averages a daily high of 11.6°C. Expect roughly 7.9 wet days totalling 60.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Yamatokōriyama is April–June.
Based on NARA, JA (11.9km), 1995–2024. 25 years of December data.