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April Weather in San Juan, United States

Last updated: June 24, 2025

In San Juan, United States, the average temperature for April is a pleasant 25°C (78°F). However, be prepared for a wide range; temperatures can dip to a chilly 8°C (47°F) or soar to a scorching 41°C (107°F). Expect about 31 mm (1.2 in) of precipitation spread over 4 days, accompanied by an average humidity level of 77%. Stay cool and enjoy the season!

April Temperature in San Juan

In April in San Juan, the average temperature is 25°C (78°F), with maximums reaching up to 41°C (107°F) and minimums dropping as low as 8°C (47°F). Be prepared for a wide range of temperatures when traveling to San Juan during this month.

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

The chart illustrates April 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, April typically has an average temperature of 25°C (78°F), with highs reaching up to 41°C (107°F) and lows dropping to around 8°C (47°F).
JanFebMarAprMayJunJulAugSepOctNovDec616572778285868884776964
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.

April Precipitation in San Juan

In San Juan in April, the total precipitation amount is 31 mm (1.2 in) over a span of 4 days.

April Precipitation Trends in San Juan

The chart displays monthly precipitation patterns in San Juan, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In San Juan, April typically receives around 31 mm (1.2 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec2021313187811002296513021
Data source: Precipitation data for April generated using information from the Copernicus Climate Change Service.
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April Humidity in San Juan

In San Juan in April humidity is 77%. With an average temperature of 25°C (78°F), this humidity feels like a warm, sticky embrace that can quickly sap your energy, making outdoor activities more challenging and requiring frequent breaks to stay hydrated and cool.

April Average Humidity in San Juan

This chart illustrates the average monthly humidity levels in San Juan, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in San Juan is approximately 77%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec83%79%76%77%80%73%66%65%73%76%80%86%
Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in San Juan

In San Juan in April, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in San Juan.

Maximum UV Index Levels in San Juan for April

The chart shows the monthly maximum UV Index (UVI) for San Juan in April, 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 April, the maximum UV index in San Juan typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec6910111212121211976
Data source: San Juan April 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 April 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 April’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 April’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather16°C (62°F)20 mm (0.8 inches)83%high
February Weather18°C (65°F)21 mm (0.8 inches)79%very high
March Weather22°C (72°F)31 mm (1.2 inches)76%very high
April Weather25°C (78°F)31 mm (1.2 inches)77%extreme
May Weather28°C (83°F)87 mm (3.4 inches)80%extreme
June Weather30°C (86°F)81 mm (3.2 inches)73%extreme
July Weather30°C (87°F)100 mm (3.9 inches)66%extreme
August Weather31°C (88°F)22 mm (0.9 inches)65%extreme
September Weather29°C (84°F)96 mm (3.8 inches)73%extreme
October Weather25°C (77°F)51 mm (2.0 inches)76%very high
November Weather20°C (69°F)30 mm (1.2 inches)80%high
December Weather18°C (64°F)21 mm (0.8 inches)86%high

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