In September, San Francisco El Alto typically sees daytime highs of 18.4°C and overnight lows around 8.2°C. Compared to the annual average high of 18.8°C, September runs -0.3°C.
September in San Francisco El Alto averages a daytime high of 18.4°C and an overnight low of 8.2°C.
September runs -0.3°C compared to San Francisco El Alto's annual average high of 18.8°C, ranking #8 of 12 months by warmth.
Plan for daytime highs near 18.4°C and cooler evenings around 8.2°C.