In September, San Luis typically sees daytime highs of 31.6°C and overnight lows around 22.4°C. Compared to the annual average high of 30.3°C, September runs +1.3°C.
September in San Luis averages a daytime high of 31.6°C and an overnight low of 22.4°C.
September runs +1.3°C compared to San Luis's annual average high of 30.3°C, ranking #3 of 12 months by warmth.
Plan for daytime highs near 31.6°C and cooler evenings around 22.4°C.