Austin Weather in December
December usually brings the first frosts of the season to Austin, Texas. Most days though, Austin basks in mild weather.
This page gives detailed information on the typical December temperature, precipitation, sun, humidity, wind and storms for Austin. The numbers here are historical averages based on climate data gathered at Camp Mabry, located at few miles from downtown Austin.
Temperature
| 64 °F | December average high | 18 °C |
| 43 °F | December average low | 6 °C |
| 20 days | 60 °F max. or more (16 °C) |
| 14 days | 40 °F min. or less (4 °C) |
On most December days, Austin warms up to over 50 degrees Fahrenheit (10 degrees Celsius). The city averages ten days this month when the thermometer reaches into the 70s °F (over 21 °C). For one or two days on average, the temperature does get as high as 80 °F (27 °C) this time of year.
The thermometer dips to freezing or below on an average of 3 nights. But December normally doesn't get as cold as 20 °F (-8 °C).
Rain
| 2.7 in | total precipitation | 69 mm |
| 8 days | of rain |
Half the time, Austin receives 0.7 to 4.3 inches (19 to 108 mm) of rainfall in December. One in four years has drier weather, while another one in four is wetter. None of the precipitation normally falls as snow.
Sun
| 49 % | sunshine |
| 10 days | clear skies |
December is one of the cloudiest months at Austin. Even so, half the time the weather is sunny. The sun's rays reach the ground during 49 percent of daylight hours on average, for a total of 155 hours in the month. Typically on 10 days this month the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in December at Austin averages 10 hours and 13 minutes a day. The shortest days of the year, from around December 16th to 26th, last 10 hours and 12 minutes from sunrise to sunset.
Humidity
| 68 % | December average humidity |
The relative humidity in Austin during December usually peaks at 80 percent in the morning then drops to 52 percent by mid afternoon.
| Local Time | 12 am | 3 am | 6 am | 9 am | 12 pm | 3 pm | 6 pm | 9 pm |
| Humidity % | 73 | 77 | 80 | 75 | 59 | 52 | 58 | 68 |
Wind
| 8.2 mph | December wind speed average | 13.2 kph |
December is less windy than most other months in Austin.
Storms
| 2 days | rainfall of 0.5 inches (13 mm) or more |
| 1 day | with thunderstorms in December |
In some Decembers, Austin doesn't see a thunderstorm.
Reference
The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.