December weather forecastSan Marcos, TX
December
Weather in December
December, the first month of the winter in San Marcos, is still a mild month, with an average temperature ranging between max 60.4°F (15.8°C) and min 45.5°F (7.5°C).Temperature
The advent of December brings a subtle shift in temperature, with the average high moving from a pleasant 68.2°F (20.1°C) in November to a mild 60.4°F (15.8°C). The nighttime temperature, during December, averages of 45.5°F (7.5°C).Humidity
In December, the average relative humidity in San Marcos, Texas, is 72%.Rainfall
In December, the rain falls for 11.7 days. Throughout December, 1.57" (40mm) of precipitation is accumulated. In San Marcos, during the entire year, the rain falls for 151.8 days and collects up to 26.89" (683mm) of precipitation.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. Throughout the year, there are 0.7 snowfall days, and 0.28" (7mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 10h and 18min of daylight.On the first day of the month, sunrise is at 7:10 am and sunset at 5:31 pm. On the last day of December, sunrise is at 7:27 am and sunset at 5:43 pm CST.
Sunshine
The month with the least sunshine is December, with an average of 5.2h of sunshine.UV index
The month with the lowest UV index is December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: A daily maximum UV index of 3 in December translates into the following instructions:
Undertake precautions - It is suggested to shield oneself from sunburn. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
San Marcos, TX
- Average high temperature in December: 60.4°F
The warmest month (with the highest average high temperature) is August (95.9°F).
The month with the lowest average high temperature is January (59.9°F).
- Average low temperature in December: 45.5°F
The month with the highest average low temperature is August (74.7°F).
The coldest month (with the lowest average low temperature) is January (42.8°F).
Average pressure in December
San Marcos, 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 (29.9"Hg).
Average wind speed in December
San Marcos, TX
- Average wind speed in December: 8.1mph
The windiest month (with the highest average wind speed) is February (9.1mph).
The calmest month (with the lowest average wind speed) is September (6.1mph).
Average humidity in December
San Marcos, TX
- Average humidity in December: 72%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is August (62%).
Average rainfall in December
San Marcos, TX
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is May (4.57").
The driest month (with the least rainfall) is February (1.1").
Average rainfall days in December
San Marcos, TX
- Average rainfall days in December: 11.7 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in December
San Marcos, TX
- Average snowfall in December: 0.04"
The months with the highest snowfall are January and February (0.12").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in December
San Marcos, 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 Marcos, 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 12min
The months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 12min).
Average sunshine days in December
San Marcos, TX
- Average sunshine days in December: 17.1 days
The month with the most sunshine days is January (19.4 days).
The month with the least sunshine days is May (11.9 days).
Average UV index in December
San Marcos, 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 Marcos, TX
- Average cloud cover in December: 43
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in December
San Marcos, TX
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
