March in San Juan averages a daily high of 32.9°C with nights around 22.7°C. Expect roughly 4.1 wet days totalling 39.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit San Juan is January–February.
Based on SCIENCE GARDEN, RP (4.1km), 1995–2024. 25 years of March data.