September in San Cristóbal de las Casas averages a daily high of 24.5°C with nights around 11.9°C. Expect roughly 15.4 wet days totalling 134.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit San Cristóbal de las Casas is November–April.
Based on SN. CRISTOBAL LAS CASAS CHIS, MX (2.3km), 1995–2024. 21 years of September data.