January Weather in San Antonio, Mexico

Last updated: August 27, 2025

In January, the average temperature in San Antonio, Mexico is a mild 13°C (55°F), with temperatures ranging from a chilly -1°C (30°F) to a warm 27°C (82°F). Expect 7 mm (0.3 in) of precipitation over the course of 2 days, and enjoy an average humidity level of 74%.

January Temperature in San Antonio

In January in San Antonio, the average temperature is 13°C (55°F). Maximums can reach 27°C (82°F), while minimums can drop to as low as -1°C (30°F). This variability makes it essential to pack both warm and light clothing for a comfortable trip.

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 13°C (55°F), with highs reaching up to 27°C (82°F) and lows dropping to around -1°C (30°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 7 mm (0.3 in) over a period of 2 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 7 mm (0.3 inches) of precipitation spread over approximately 2 days.

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

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Millimeters (mm) Inches (in)

January Humidity in San Antonio

In San Antonio in January, humidity is 74%. With an average temperature of 13°C (55°F), this humidity feels like a damp blanket wrapping around you, making outdoor activities somewhat uncomfortable and demanding frequent breaks in shaded areas.

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 74%, 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 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the 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 9, which falls under the very 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	13°C (55°F)	7 mm (0.3 inches)	74%	very high
February Weather	15°C (60°F)	10 mm (0.4 inches)	65%	extreme
March Weather	18°C (64°F)	14 mm (0.5 inches)	58%	extreme
April Weather	20°C (68°F)	9 mm (0.4 inches)	58%	extreme
May Weather	21°C (71°F)	45 mm (1.8 inches)	67%	extreme
June Weather	20°C (68°F)	120 mm (4.7 inches)	76%	extreme
July Weather	19°C (67°F)	106 mm (4.2 inches)	67%	extreme
August Weather	20°C (67°F)	77 mm (3.0 inches)	68%	extreme
September Weather	18°C (65°F)	121 mm (4.8 inches)	81%	extreme
October Weather	17°C (63°F)	63 mm (2.5 inches)	83%	extreme
November Weather	15°C (58°F)	23 mm (0.9 inches)	84%	very high
December Weather	13°C (55°F)	7 mm (0.3 inches)	81%	very high