nomadseason

January Weather in San Juan, Peru

Last updated: August 27, 2025

In January, the average temperature in San Juan, Peru hovers around 8°C (47°F), making it a cool and crisp time of year. Expect temperatures to dip as low as -2°C (29°F) and reach a comfortable high of 19°C (66°F). This month also brings substantial precipitation, with 254 mm (10.0 in) falling over approximately 25 days, contributing to an average humidity level of 89%. Be prepared for a moody climate that keeps the air fresh and lush!

January Temperature in San Juan

In January in San Juan, the average temperature is 8°C (47°F). Maximums can reach 19°C (66°F) and minimums can be as low as -2°C (29°F). It's advisable to pack layers to stay comfortable while exploring the varied climate during your travels.

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 8°C (47°F), with highs reaching up to 19°C (66°F) and lows dropping to around -2°C (29°F).
JanFebMarAprMayJunJulAugSepOctNovDec474747454443424345464647
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 precipitation amount is 254 mm (10.0 in), occurring over a span 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 254 mm (10.0 inches) of precipitation spread over approximately 25 days.
JanFebMarAprMayJunJulAugSepOctNovDec254268323142724941369310683146
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 8°C (47°F), this humidity feels like a chilly dampness that clings to your skin, making outdoor activities less enjoyable and prompting frequent breaks indoors to warm up.

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%90%90%90%84%67%53%47%53%67%75%83%
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.
JanFebMarAprMayJunJulAugSepOctNovDec181818161311121416171818
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 Weather8°C (47°F)254 mm (10.0 inches)89%extreme
February Weather8°C (47°F)268 mm (10.6 inches)90%extreme
March Weather8°C (47°F)323 mm (12.7 inches)90%extreme
April Weather7°C (46°F)142 mm (5.6 inches)90%extreme
May Weather6°C (44°F)72 mm (2.8 inches)84%extreme
June Weather6°C (43°F)49 mm (1.9 inches)67%extreme
July Weather6°C (43°F)41 mm (1.6 inches)53%extreme
August Weather6°C (44°F)35 mm (1.4 inches)47%extreme
September Weather7°C (46°F)93 mm (3.7 inches)53%extreme
October Weather8°C (46°F)106 mm (4.2 inches)67%extreme
November Weather8°C (47°F)83 mm (3.3 inches)75%extreme
December Weather8°C (47°F)146 mm (5.7 inches)82%extreme

Compare San Juan's Climate with Cities Worldwide