January in Viacha averages a daily high of 15.3°C with nights around 4.3°C. Expect roughly 20.6 wet days totalling 125.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Viacha is April–November.
Based on EL ALTO INTERNATIONAL, BL (19.1km), 1995–2024. 18 years of January data.