December weather forecastSan Antonio, TX
December
Weather in December
December is the coolest month in San Antonio, Texas. The city transitions into wintry conditions, with shorter days and longer nights, in line with the winter solstice towards the end of the month. It's the only month to witness any snowfall, with a minimal average of 0.04in. Embracing the festive spirit, San Antonio becomes a winter wonderland, beautifully lit and decorated for the holiday season. Despite the cold, the city's charm makes it an attractive destination for holiday travelers.Temperature
December's arrival aligns with a minor decrease in average high-temperatures, from November's pleasant 69.8°F (21°C) to an enjoyable 62.4°F (16.9°C). During the nights in December, an average low-temperature of 46.9°F (8.3°C) is observed.Humidity
In San Antonio, the average relative humidity in December is 69%.Rainfall
In December, the rain falls for 9.9 days. Throughout December, 1.1" (28mm) of precipitation is accumulated. Throughout the year, there are 144.5 rainfall days, and 22.6" (574mm) of precipitation is accumulated.Snowfall
January, February and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In San Antonio, during the entire year, snow falls for 0.7 days and aggregates up to 0.2" (5mm) of snow.Daylight
December has the shortest days of the year, with an average of 10h and 18min of daylight.On the first day of December, sunrise is at 7:11 am and sunset at 5:35 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:46 pm CST.
Sunshine
December has the least sunshine of the year, with an average of 5.3h of sunshine.UV index
With an average maximum UV index of 3, December is the month with the lowest UV index. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: The maximum UV index of 3 during December leads to these instructions:
Ensure safety - Sun damage prevention is strongly urged. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
San Antonio, TX
- Average high temperature in December: 62.4°F
The warmest month (with the highest average high temperature) is August (96.6°F).
The month with the lowest average high temperature is January (61.7°F).
- Average low temperature in December: 46.9°F
The month with the highest average low temperature is August (75.7°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).
Average pressure in December
San Antonio, TX
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
San Antonio, TX
- Average wind speed in December: 7.7mph
The windiest month (with the highest average wind speed) is May (9mph).
The calmest month (with the lowest average wind speed) is September (6.5mph).
Average humidity in December
San Antonio, TX
- Average humidity in December: 69%
The month with the highest relative humidity is May (73%).
The month with the lowest relative humidity is August (59%).
Average rainfall in December
San Antonio, TX
- Average rainfall in December: 1.1"
The wettest month (with the highest rainfall) is May (3.66").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in December
San Antonio, TX
- Average rainfall days in December: 9.9 days
The month with the highest number of rainy days is September (17 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in December
San Antonio, TX
- Average snowfall in December: 0.04"
The months with the highest snowfall are January and February (0.08").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in December
San Antonio, TX
- Average snowfall days in December: 0.1 days
The months with the highest number of snowfall days are January and February (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
San Antonio, TX
- Average daylight in December: 10h and 18min
The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).
- Average sunshine in December: 5h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
San Antonio, TX
- Average sunshine days in December: 19 days
The month with the most sunshine days is January (20.3 days).
The months with the least sunshine days are May and September (11.8 days).
Average UV index in December
San Antonio, 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
San Antonio, TX
- Average cloud cover in December: 41
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in December
San Antonio, 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).
