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January Weather in San Juan, Peru

Last updated: August 27, 2025

In San Juan, Peru, the average temperature in January hovers around 21°C (70°F). Expect a cozy minimum of 17°C (63°F) and a pleasant maximum of 28°C (83°F). Be prepared for some rain, as the month sees about 14 mm (0.6 in) of precipitation over 4 days. With an average humidity of 85%, the air will feel quite refreshing!

January Temperature in San Juan

In January in San Juan, the average temperature is 21°C (70°F). Maximum temperatures can reach 28°C (83°F), while minimums can drop to as low as 17°C (63°F). This moderate climate makes San Juan an ideal destination for enjoyable outdoor activities and sightseeing.

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 21°C (70°F), with highs reaching up to 28°C (83°F) and lows dropping to around 17°C (63°F).
JanFebMarAprMayJunJulAugSepOctNovDec707170666361595858606266
Data source: Temperature data for San Juan generated using information from the Copernicus Climate Change Service.
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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 14 mm (0.6 in) spread over a duration 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 14 mm (0.6 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec141153691166546
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in San Juan

In San Juan in January, humidity is 85%. With an average temperature of 21°C (70°F), this humidity feels like a warm, heavy blanket enveloping you, making travel feel slightly stifling and requiring frequent breaks to refresh in the shade or near water.

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 85%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%86%88%85%78%76%74%74%78%82%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 reaches an alarming 15, which falls into the extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take precautions. For 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 15, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec1515141310991113141515
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 Weather21°C (70°F)14 mm (0.6 inches)85%extreme
February Weather21°C (71°F)11 mm (0.4 inches)85%extreme
March Weather21°C (70°F)5 mm (0.2 inches)86%extreme
April Weather19°C (67°F)3 mm (0.1 inches)88%extreme
May Weather17°C (63°F)5 mm (0.2 inches)85%very high
June Weather16°C (61°F)9 mm (0.4 inches)78%very high
July Weather15°C (59°F)11 mm (0.4 inches)75%very high
August Weather14°C (58°F)6 mm (0.2 inches)73%extreme
September Weather15°C (58°F)6 mm (0.2 inches)74%extreme
October Weather15°C (60°F)5 mm (0.2 inches)78%extreme
November Weather17°C (63°F)4 mm (0.2 inches)82%extreme
December Weather19°C (66°F)6 mm (0.2 inches)83%extreme

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