In December, Round Rock typically sees daytime highs of 16.8°C and overnight lows around 3.8°C. Compared to the annual average high of 25.8°C, December runs -9.0°C.
December in Round Rock averages a daytime high of 16.8°C and an overnight low of 3.8°C.
December runs -9.0°C compared to Round Rock's annual average high of 25.8°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 16.8°C and cooler evenings around 3.8°C.