In December, San Antonio typically sees daytime highs of 21.9°C and overnight lows around 11.2°C. Compared to the annual average high of 18.7°C, December runs +3.1°C.
December in San Antonio averages a daytime high of 21.9°C and an overnight low of 11.2°C.
December runs +3.1°C compared to San Antonio's annual average high of 18.7°C, ranking #3 of 12 months by warmth.
Plan for daytime highs near 21.9°C and cooler evenings around 11.2°C.