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March Weather in San Juan, United States

Last updated: June 24, 2025

In March, the average temperature in San Juan, United States hovers around 6°C (43°F), with a minimum drop to a chilly -10°C (14°F) and a maximum rise to a pleasant 23°C (73°F). Expect 24 mm (1.0 in) of precipitation over 6 days, contributing to an average humidity of 66%. Be prepared for a variety of weather conditions during your visit!

March Temperature in San Juan

In March in San Juan, the average temperature is 6°C (43°F). The maximum can reach 23°C (73°F) and the minimum can be as low as -10°C (14°F). It's advisable to pack layers to prepare for a wide range of temperatures while exploring this destination.

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

The chart illustrates March 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, March typically has an average temperature of 6°C (43°F), with highs reaching up to 23°C (73°F) and lows dropping to around -10°C (14°F).
JanFebMarAprMayJunJulAugSepOctNovDec293242516070727165524132
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.

March Precipitation in San Juan

In San Juan in March, the precipitation amount is 24 mm (1.0 in) spread over a period of 6 days.

March Precipitation Trends in San Juan

The chart displays monthly precipitation patterns in San Juan, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In San Juan, March typically receives around 24 mm (1.0 inches) of precipitation spread over approximately 6 days.
JanFebMarAprMayJunJulAugSepOctNovDec242424231815342427272319
Data source: Precipitation data for March generated using information from the Copernicus Climate Change Service.
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March Humidity in San Juan

In San Juan in March, humidity is 66%. With an average temperature of 6°C (43°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities less enjoyable and requiring warm layers for comfort while traveling.

March Average Humidity in San Juan

This chart illustrates the average monthly humidity levels in San Juan, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in San Juan is approximately 66%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec78%79%66%60%57%55%57%65%72%78%81%79%
Data source: Humidity data for March generated using information from the Copernicus Climate Change Service.

March UV Index in San Juan

In San Juan in March, 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 March

The chart shows the monthly maximum UV Index (UVI) for San Juan in March, 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 March, the maximum UV index in San Juan typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec5810111213131211864
Data source: San Juan March 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 March 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 March’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 March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)24 mm (0.9 inches)78%moderate
February Weather0°C (33°F)24 mm (0.9 inches)79%very high
March Weather6°C (43°F)24 mm (1.0 inches)66%very high
April Weather11°C (51°F)22 mm (0.9 inches)60%extreme
May Weather16°C (60°F)18 mm (0.7 inches)57%extreme
June Weather21°C (70°F)15 mm (0.6 inches)55%extreme
July Weather22°C (73°F)34 mm (1.3 inches)56%extreme
August Weather21°C (71°F)23 mm (0.9 inches)65%extreme
September Weather18°C (65°F)27 mm (1.0 inches)72%extreme
October Weather11°C (52°F)27 mm (1.1 inches)78%very high
November Weather5°C (41°F)23 mm (0.9 inches)81%high
December Weather0°C (32°F)19 mm (0.7 inches)79%moderate

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