January Weather in San Antonio, United States

Last updated: June 24, 2025

In January, the average temperature in San Antonio, United States hovers around 16°C (60°F). However, be prepared for a range: temperatures can dip to a chilly -4°C (25°F) or soar to a warm 29°C (84°F). During this month, precipitation averages 43 mm (1.7 in) over 4 days, while the average humidity lingers at a notable 83%. Embrace the variety this month brings!

January Temperature in San Antonio

In January in San Antonio, the average temperature is 16°C (60°F). Maximum temperatures can reach 29°C (84°F), while minimums may drop as low as -4°C (25°F). Be prepared for a wide range of weather conditions if you're planning to travel during this time.

January Weather in San Antonio: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in San Antonio, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Antonio, January typically has an average temperature of 16°C (60°F), with highs reaching up to 29°C (84°F) and lows dropping to around -4°C (25°F).

Data source: Temperature data for San Antonio generated using information from the Copernicus Climate Change Service.

January Precipitation in San Antonio

In San Antonio in January, the precipitation amount is 43 mm (1.7 in) over the course of 4 days.

January Precipitation Trends in San Antonio

The chart displays monthly precipitation patterns in San Antonio, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In San Antonio, January typically receives around 43 mm (1.7 inches) of precipitation spread over approximately 4 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in San Antonio

In San Antonio in January humidity is 83%. With an average temperature of 16°C (60°F), this humidity feels like a warm, heavy blanket wrapping around you, making outdoor activities a bit uncomfortable for traveling.

January Average Humidity in San Antonio

This chart illustrates the average monthly humidity levels in San Antonio, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in San Antonio is approximately 83%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in San Antonio

In San Antonio in January, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in San Antonio, you can refer to this Hourly UV Index in San Antonio.

Maximum UV Index Levels in San Antonio for January

The chart shows the monthly maximum UV Index (UVI) for San Antonio in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in San Antonio typically reaches 6, which falls under the high exposure category.

Data source: San Antonio January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How January Weather in San Antonio Compares to Other Months

Weather in San Antonio varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in San Antonio, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in San Antonio, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	16°C (60°F)	43 mm (1.7 inches)	83%	high
February Weather	19°C (66°F)	69 mm (2.7 inches)	80%	very high
March Weather	20°C (68°F)	20 mm (0.8 inches)	75%	very high
April Weather	23°C (73°F)	77 mm (3.0 inches)	70%	extreme
May Weather	25°C (78°F)	123 mm (4.8 inches)	68%	extreme
June Weather	27°C (81°F)	223 mm (8.8 inches)	75%	extreme
July Weather	27°C (81°F)	276 mm (10.8 inches)	79%	extreme
August Weather	28°C (82°F)	247 mm (9.7 inches)	81%	extreme
September Weather	27°C (81°F)	189 mm (7.4 inches)	83%	extreme
October Weather	25°C (77°F)	82 mm (3.2 inches)	81%	very high
November Weather	20°C (68°F)	49 mm (1.9 inches)	82%	high
December Weather	17°C (64°F)	70 mm (2.8 inches)	84%	moderate