December in Tarija averages a daily high of 29.1°C with nights around 14.5°C. Expect roughly 14 wet days totalling 126.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Tarija is April–October.
Based on TARIJA, BL (3.5km), 1995–2024. 14 years of December data.