Climate averages 1991–2020
Round Rock weather
in December.
A mild, moderately wet month: the 11th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a mild month in Round Rock: daytime highs average 16.3°C and nights cool to about 6.8°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 70 mm of rain on roughly 8 days, which makes December a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 13 min on an average December day.
The nearest other city in this atlas is Austin (28 km away). In December its highs average 16.6°C, about as warm as Round Rock, with 70 mm of rain.
Among the 498 cities listed in the United States, Round Rock ranks joint 128th of 498 for the warmest December highs and joint 252nd of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Round Rock is 5.7°C warmer than that mean.
From December to January, average highs fall by 0.7°C to 15.6°C, and monthly rainfall falls from 70 mm to 59 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Round Rock climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 15.6°C5.8°C | 5.8°C | 59 | 6.8 | 10.410 h |
| February | 17.8°C7.6°C | 7.6°C | 61 | 7.4 | 11.111 h |
| March | 21.4°C11.0°C | 11.0°C | 74 | 8.8 | 12.012 h |
| April | 25.5°C14.9°C | 14.9°C | 76 | 8.2 | 12.913 h |
| May | 28.9°C19.3°C | 19.3°C | 110 | 10.8 | 13.714 h |
| June | 32.4°C22.7°C | 22.7°C | 72 | 8.7 | 14.114 h |
| July | 34.5°C24.2°C | 24.2°C | 39 | 5.7 | 13.914 h |
| August | 34.7°C24.6°C | 24.6°C | 54 | 5.8 | 13.313 h |
| September | 31.1°C21.5°C | 21.5°C | 74 | 7.4 | 12.412 h |
| October | 26.4°C16.4°C | 16.4°C | 86 | 7.1 | 11.511 h |
| November | 20.3°C10.8°C | 10.8°C | 69 | 6.6 | 10.611 h |
| December, selected | 16.3°C6.8°C | 6.8°C | 70 | 7.5 | 10.210 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Austin in DecemberUnited States · 28 kmHigh 16.6°C · Low 6.9°C · 70 mm rain
- Killeen in DecemberUnited States · 68 kmHigh 15.6°C · Low 5.9°C · 72 mm rain
- Temple in DecemberUnited States · 73 kmHigh 15.6°C · Low 6.0°C · 82 mm rain
- New Braunfels in DecemberUnited States · 99 kmHigh 17.1°C · Low 7.6°C · 67 mm rain
- Waco in DecemberUnited States · 126 kmHigh 15.5°C · Low 6.0°C · 83 mm rain
- Bryan in DecemberUnited States · 127 kmHigh 16.3°C · Low 6.9°C · 95 mm rain
- College Station in DecemberUnited States · 129 kmHigh 16.4°C · Low 7.0°C · 95 mm rain
- San Antonio in DecemberUnited States · 144 kmHigh 17.5°C · Low 7.8°C · 63 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Round Rock) is explained once on the Round Rock year overview and on the Sources, method and limits page.