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May Weather in San Juan, Peru

Last updated: August 27, 2025

In May, the average temperature in San Juan, Peru is a pleasant 17°C (63°F). Expect temperatures to drop to a minimum of 12°C (54°F) and rise to a maximum of 23°C (74°F). With an average humidity of 85%, the air can feel quite moist, although there’s minimal rainfall, with only 5 mm (0.2 in) expected over 0 days.

May Temperature in San Juan

In May in San Juan, the average temperature is 17°C (63°F). Maximums can reach 23°C (74°F), and minimums can be as low as 12°C (54°F). This mild climate makes San Juan an ideal destination for travelers seeking comfortable weather for exploration and outdoor activities.

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

The chart illustrates May 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, May typically has an average temperature of 17°C (63°F), with highs reaching up to 23°C (74°F) and lows dropping to around 12°C (54°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.

May Precipitation in San Juan

In San Juan in May, the precipitation amount is 5 mm (0.2 in) during a span of 0 days.

May Precipitation Trends in San Juan

The chart displays monthly precipitation patterns in San Juan, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In San Juan, May typically receives around 5 mm (0.2 inches) of precipitation spread over approximately 0 days.
JanFebMarAprMayJunJulAugSepOctNovDec141153691166546
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in San Juan

In San Juan in May humidity is 85%. With an average temperature of 17°C (63°F), this humidity feels like a warm, enveloping blanket that clings to your skin, making outdoor activities a bit stifling and encouraging frequent breaks in shaded areas or air-conditioned spaces for travelers.

May Average Humidity in San Juan

This chart illustrates the average monthly humidity levels in San Juan, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, 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 May generated using information from the Copernicus Climate Change Service.

May UV Index in San Juan

In San Juan in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in San Juan.

Maximum UV Index Levels in San Juan for May

The chart shows the monthly maximum UV Index (UVI) for San Juan in May, 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 May, the maximum UV index in San Juan typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec1515141310991113141515
Data source: San Juan May 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 May 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 May’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 May’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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