December weather forecastRound Rock, TX
December
Weather in December
December brings the onset of winter to Round Rock, Texas. The air is filled with the unmistakable chill of the season, and the days start to shorten as the year draws to a close. Outdoor activities start to experience a lull as residents prefer the warmth of indoor spaces. Rainfall remains relatively stable when compared with November, but cold winds become prominent. Additionally, with an occasional slight snowfall of nearly no inches, December marks the culmination of the year in a truly winter fashion.Temperature
Round Rock's December weather features a light decline in high-temperatures, reducing from a comfortable 67.1°F (19.5°C) in November to a moderate 59.4°F (15.2°C). In the month of December, Round Rock witnesses a consistent average low-temperature of 44.4°F (6.9°C).Humidity
The average relative humidity in December is 70%.Rainfall
In Round Rock, in December, during 9.6 rainfall days, 1.65" (42mm) of precipitation is typically accumulated. In Round Rock, during the entire year, the rain falls for 139.3 days and collects up to 26.18" (665mm) of precipitation.Snowfall
In Round Rock, snow does not fall in March through December.Daylight
The month with the shortest days is December, with an average of 10h and 12min of daylight.On the first day of December in Round Rock, sunrise is at 7:10 am and sunset at 5:29 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 5:40 pm CST.
Sunshine
With an average of 5.3h of sunshine, December has the least sunshine of the year.UV index
December is the month with the lowest UV index in Round Rock, with an average maximum UV index of 3. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A typical high UV index of 3 in December suggests the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Round Rock, TX
- Average high temperature in December: 59.4°F
The warmest month (with the highest average high temperature) is August (96.1°F).
The month with the lowest average high temperature is January (58.6°F).
- Average low temperature in December: 44.4°F
The month with the highest average low temperature is August (75.4°F).
The coldest month (with the lowest average low temperature) is January (42.4°F).
Average pressure in December
Round Rock, TX
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Round Rock, TX
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is March (9.8mph).
The calmest month (with the lowest average wind speed) is September (6.5mph).
Average humidity in December
Round Rock, TX
- Average humidity in December: 70%
The month with the highest relative humidity is May (75%).
The month with the lowest relative humidity is August (59%).
Average rainfall in December
Round Rock, TX
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in December
Round Rock, TX
- Average rainfall days in December: 9.6 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in December
Round Rock, TX
- Average snowfall in December: 0"
The month with the highest snowfall is February (0.24").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in December
Round Rock, TX
- Average snowfall days in December: 0.3 days
The month with the highest number of snowfall days is February (0.8 days).
The months with the least snowfall days are March, April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Round Rock, TX
- Average daylight in December: 10h and 12min
The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).
- Average sunshine in December: 5h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
Round Rock, TX
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is January (21.1 days).
The months with the least sunshine days are April, May and September (13.3 days).
Average UV index in December
Round Rock, TX
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in December
Round Rock, TX
- Average cloud cover in December: 42
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in December
Round Rock, TX
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
