In December, San Tan Valley typically sees daytime highs of 18.9°C and overnight lows around 3.3°C. Compared to the annual average high of 29.7°C, December runs -10.9°C.
December in San Tan Valley averages a daytime high of 18.9°C and an overnight low of 3.3°C.
December runs -10.9°C compared to San Tan Valley's annual average high of 29.7°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 18.9°C and cooler evenings around 3.3°C.