January Weather in San Juan, Mexico

Last updated: August 27, 2025

In San Juan, Mexico, the average temperature in January hovers around 17°C (63°F). While you might experience a refreshing minimum of 1°C (34°F), be prepared for warmer days reaching up to a balmy 31°C (87°F). Expect light precipitation of about 11 mm (0.4 in) spread over just 1 day, accompanied by an average humidity of 74%, adding to the atmospheric richness of the season.

January Temperature in San Juan

In January in San Juan, the average temperature is 17°C (63°F). Maximum temperatures can reach 31°C (87°F), while minimums can dip as low as 1°C (34°F). Be prepared for a wide range of temperatures when traveling to San Juan this month!

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 17°C (63°F), with highs reaching up to 31°C (87°F) and lows dropping to around 1°C (34°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 precipitation amount is 11 mm (0.4 in) over the course of one day.

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 11 mm (0.4 inches) of precipitation spread over approximately 1 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 74%. With an average temperature of 17°C (63°F), this humidity feels like a gentle embrace, making outdoor exploration comfortable yet slightly enveloped in warmth, perfect for leisurely strolls but requiring ample hydration for prolonged activities.

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 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 Juan

In San Juan in January, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the 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 7, 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	17°C (63°F)	11 mm (0.4 inches)	74%	high
February Weather	18°C (65°F)	37 mm (1.5 inches)	66%	very high
March Weather	20°C (68°F)	2 mm (0.1 inches)	61%	extreme
April Weather	22°C (72°F)	1 mm (0.0 inches)	56%	extreme
May Weather	24°C (76°F)	2 mm (0.1 inches)	61%	extreme
June Weather	26°C (78°F)	73 mm (2.9 inches)	73%	extreme
July Weather	24°C (76°F)	217 mm (8.6 inches)	82%	extreme
August Weather	25°C (76°F)	255 mm (10.0 inches)	83%	extreme
September Weather	24°C (75°F)	166 mm (6.5 inches)	83%	extreme
October Weather	23°C (74°F)	68 mm (2.7 inches)	78%	extreme
November Weather	21°C (69°F)	13 mm (0.5 inches)	77%	very high
December Weather	18°C (64°F)	24 mm (0.9 inches)	78%	high