San Antonio Weather in January

San Antonio, Texas has comfortable weather during January even though it's the coldest and cloudiest time of year. Daytime temperatures are often warm. And despite the cloud, rain is often light.

This page gives detailed information on the typical January temperature, precipitation, sun, humidity, wind and storms for San Antonio. The numbers here are historical averages based on climate data gathered at the San Antonio International Airport, located a few miles north of the city center.

Temperature Weather iconTemperature

63 °F January average high 17 °C
41 °F January average low 5 °C

The coldest temperatures overall for the year which began in late December extend until January 20th. On these dates daily highs average 63 degrees Fahrenheit (17 degrees Celsius) while lows are 41 °F (5 °C)

21 days 60 °F max. or more (16 °C)
16 days 40 °F min. or less (4 °C)

San Antonio typically has 11 days in January when the thermometer reaches into the 70s °F (over 21 °C). Temperatures in the 80s F (above 27 °C) occur on an average of one day during the month.

The thermometer dips to freezing or below on an average of 5 nights. Although uncommon, January can get as cold as 20 °F (-8 °C).

Rainy Weather iconPrecipitation

2.0 in total precipitation 50 mm
7 days of rain

This is one of the driest months for San Antonio. Half the time, the city receives 0.4 to 2.9 inches (10 to 72 mm) of rainfall in January. One in four years has drier weather, while another one in four is wetter.

In some years, San Antonio does get snow this month.

Sunny Weather iconSun

47 % sunshine
9 days clear skies

January is San Antonio's cloudiest time of year. The sun's rays reach the ground during 47 percent of daylight hours on average, for a monthly total of 153 hours. Typically on 9 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in January at San Antonio lasts for 10 hours and 30 minutes a day on average. The shortest day of the month is the 1st with 10 hours and 18 minutes of daylight. By the end of the month, the days have lengthened to 10:48 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humid Weather iconHumidity

67 % January average humidity

The relative humidity in San Antonio during January usually peaks at 79 percent in the morning then drops to 50 percent by mid afternoon.

Local Time12 am3 am6 am9 am12 pm3 pm6 pm9 pm
Humidity % 75 78 79 75 58 50 55 68

Windy Weather iconWind

8.8 mph January wind speed average 14.2 kph

January is a little less windy than most other months in San Antonio.

Stormy Weather iconStorms

1 day rainfall of 0.5 inches (13 mm) or more
1 day with thunderstorms in January

Storms of any kind are not common during January at San Antonio.


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.

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