January Weather in San Juan, Mexico

Last updated: August 27, 2025

In San Juan, Mexico, the average temperature in January hovers around 16°C (61°F), with a minimum low of -1°C (30°F) and a maximum peak reaching 35°C (95°F). Expect light rain with a total precipitation of 20 mm (0.8 in) spread over about 4 days. The air carries an average humidity level of 84%, creating a moist atmosphere perfect for nature enthusiasts.

January Temperature in San Juan

In January in San Juan, the average temperature is 16°C (61°F). Maximums can reach 35°C (95°F), and minimums can be as low as -1°C (30°F). Travelers should be prepared for a wide range of temperatures and pack accordingly for both warm and cool conditions.

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

The chart illustrates January temperature patterns in San Juan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Juan, January typically has an average temperature of 16°C (61°F), with highs reaching up to 35°C (95°F) and lows dropping to around -1°C (30°F).

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

January Precipitation in San Juan

In San Juan in January, the total precipitation amount is 20 mm (0.8 in) spread over a period of 4 days.

January Precipitation Trends in San Juan

The chart displays monthly precipitation patterns in San Juan, 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 Juan, January typically receives around 20 mm (0.8 inches) of precipitation spread over approximately 4 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 Juan

In San Juan in January, humidity is 84%. With an average temperature of 16°C (61°F), this humidity feels like a blanket of warmth, making travel slightly sticky but overall comfortable, as long as you stay hydrated and take breaks in the shade.

January Average Humidity in San Juan

This chart illustrates the average monthly humidity levels in San Juan, 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 Juan is approximately 84%, 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 Juan

In San Juan 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 Juan, you can refer to this Hourly UV Index in San Juan.

Maximum UV Index Levels in San Juan for January

The chart shows the monthly maximum UV Index (UVI) for San Juan 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 Juan typically reaches 6, which falls under the high exposure category.

Data source: San Juan 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 Juan Compares to Other Months

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

This table compares monthly weather conditions in San Juan, 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 (61°F)	20 mm (0.8 inches)	84%	high
February Weather	18°C (65°F)	13 mm (0.5 inches)	83%	very high
March Weather	23°C (73°F)	25 mm (1.0 inches)	78%	very high
April Weather	25°C (78°F)	46 mm (1.8 inches)	81%	extreme
May Weather	28°C (83°F)	86 mm (3.4 inches)	82%	extreme
June Weather	30°C (86°F)	86 mm (3.4 inches)	74%	extreme
July Weather	31°C (87°F)	78 mm (3.1 inches)	68%	extreme
August Weather	31°C (89°F)	16 mm (0.6 inches)	67%	extreme
September Weather	28°C (83°F)	119 mm (4.7 inches)	75%	extreme
October Weather	24°C (76°F)	56 mm (2.2 inches)	78%	very high
November Weather	20°C (68°F)	23 mm (0.9 inches)	83%	high
December Weather	17°C (64°F)	20 mm (0.8 inches)	86%	high