Weather on December 18
Round Rock, TX
55 Years of Data
Avg High
63°F
Avg Low
40°F
Warmest
2021
71°F avg
Coldest
1975
31°F avg
About This Date
December 18th in Round Rock, TX typically brings mild winter weather, with average highs around 63°F and lows near 40°F. Over 30 years of records, the warmest December 18th was in 2021 (71°F average), while the coldest was 1975 (31°F) — a 40°F range across recorded history. Rain or other precipitation has occurred on about 20% of December 18th dates historically.
Planning for December 18th in Round Rock, TX? Great weather for outdoor activities.
Warming Trend
0.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 63° | 57° | 60° | 0.2" | — |
| 2024 | 77° | 65° | 71° | — | — |
| 2023 | 69° | 34° | 51° | — | — |
| 2022 | 56° | 29° | 42° | — | — |
| 2021warmest | 76° | 67° | 71° | 0.48" | — |
| 2020 | 63° | 28° | 45° | — | — |
| 2019 | 52° | 30° | 41° | — | — |
| 2018 | 68° | 38° | 53° | — | — |
| 2017 | 57° | 44° | 51° | 0.03" | — |
| 2016 | 74° | 23° | 48° | — | — |
| 2015 | 63° | 34° | 48° | — | — |
| 2014 | 51° | 46° | 49° | 0.28" | — |
| 2013 | 70° | 37° | 53° | — | — |
| 2012 | 70° | 41° | 55° | — | — |
| 2011 | 59° | 43° | 51° | — | — |
| 2010 | 50° | 33° | 42° | — | — |
| 2009 | 54° | 41° | 47° | 0.28" | — |
| 2008 | 53° | 39° | 46° | 0.05" | — |
| 1982 | 78° | 52° | 65° | — | — |
| 1981 | 51° | 17° | 34° | — | — |
| 1980 | 80° | 50° | 65° | — | — |
| 1979 | 64° | 20° | 42° | — | — |
| 1978 | 70° | 48° | 59° | — | — |
| 1977 | 79° | 39° | 59° | — | — |
| 1976 | 65° | 52° | 58° | — | — |
| 1975coldest | 38° | 24° | 31° | — | — |
| 1974 | 68° | 41° | 55° | — | — |
| 1973 | — | 47° | — | — | — |
| 1972 | 53° | 38° | 45° | — | — |
| 1971 | 59° | 32° | 46° | — | — |
30 years of data from GEORGETOWN