nomadseason

January Weather in San Juan, Peru

Last updated: August 27, 2025

In January, the average temperature in San Juan, Peru is a mild 12°C (55°F), with a minimum of 6°C (43°F) and a maximum of 19°C (67°F). Expect a total precipitation of 229 mm (9.0 in) over about 25 days, contributing to the month's high average humidity of 89%. Whether you're braving the rain or enjoying the cool breezes, be prepared for a wet and cozy experience!

January Temperature in San Juan

In January, in San Juan, the average temperature is 12°C (55°F). The maximum can reach 19°C (67°F), while the minimum can be as low as 6°C (43°F). This mild climate makes San Juan an ideal destination for travelers seeking comfortable weather during their visit.

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 12°C (55°F), with highs reaching up to 19°C (67°F) and lows dropping to around 6°C (43°F).
JanFebMarAprMayJunJulAugSepOctNovDec545555555454555555555555
Data source: Temperature data for San Juan generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

January Precipitation in San Juan

In San Juan, in January, the total precipitation amount is 229 mm (9.0 in) over the course of 25 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 229 mm (9.0 inches) of precipitation spread over approximately 25 days.
JanFebMarAprMayJunJulAugSepOctNovDec22924424612560231926729976129
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

January Humidity in San Juan

In San Juan in January, humidity is 89%. With an average temperature of 12°C (55°F), this humidity feels like a damp chill that seeps into your bones, making it feel much colder than the thermometer suggests and potentially complicating your travel plans.

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 89%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec89%89%90%89%83%69%56%51%53%68%82%87%
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 18, which corresponds to an extreme exposure category. This means that the time to burn is just 10 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 18, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec181918171411131416181818
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.
 TemperaturePrecipitationHumidityUV
January Weather12°C (55°F)229 mm (9.0 inches)89%extreme
February Weather13°C (55°F)244 mm (9.6 inches)89%extreme
March Weather13°C (55°F)246 mm (9.7 inches)90%extreme
April Weather13°C (55°F)125 mm (4.9 inches)89%extreme
May Weather12°C (55°F)60 mm (2.3 inches)83%extreme
June Weather12°C (55°F)23 mm (0.9 inches)69%extreme
July Weather13°C (55°F)19 mm (0.7 inches)56%extreme
August Weather13°C (55°F)26 mm (1.0 inches)50%extreme
September Weather13°C (56°F)72 mm (2.9 inches)53%extreme
October Weather13°C (55°F)99 mm (3.9 inches)68%extreme
November Weather13°C (56°F)76 mm (3.0 inches)81%extreme
December Weather13°C (55°F)129 mm (5.1 inches)87%extreme

Compare San Juan's Climate with Cities Worldwide