May Weather in San Isidro, Puerto Rico

Last updated: August 31, 2025

In San Isidro, Puerto Rico, the average temperature in May is a warm 27°C (80°F). Expect a pleasant range with minimum temperatures around 23°C (73°F) and highs reaching 32°C (90°F). However, be prepared for occasional rain, as 64 mm (2.5 in) of precipitation typically falls over 13 days. With an average humidity of 75%, it's a perfect time to enjoy the vibrant atmosphere, but don't forget your sunscreen!

May Temperature in San Isidro

In May in San Isidro, the average temperature is 27°C (80°F), with maximums reaching 32°C (90°F) and minimums dropping to as low as 23°C (73°F). This climate makes it an ideal time for travelers looking to enjoy warm weather while exploring the vibrant sights of San Isidro.

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

The chart illustrates May temperature patterns in San Isidro, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Isidro, May typically has an average temperature of 27°C (80°F), with highs reaching up to 32°C (90°F) and lows dropping to around 23°C (73°F).
JanFebMarAprMayJunJulAugSepOctNovDec777677788081828282817978
Data source: Temperature data for San Isidro 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.

May Precipitation in San Isidro

In San Isidro in May, the precipitation amount is 64 mm (2.5 in) spread over 13 days.

May Precipitation Trends in San Isidro

The chart displays monthly precipitation patterns in San Isidro, 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 Isidro, May typically receives around 64 mm (2.5 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec394367566468879917314510651
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

May Humidity in San Isidro

In San Isidro in May humidity is 75%. With an average temperature of 27°C (80°F), this humidity feels like a warm, enveloping blanket that makes traveling a bit more challenging, as every step can leave you feeling sticky and in need of frequent hydration breaks.

May Average Humidity in San Isidro

This chart illustrates the average monthly humidity levels in San Isidro, 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 Isidro is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%75%74%75%75%77%80%80%79%78%78%76%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in San Isidro

In San Isidro in May, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in San Isidro, you can check here.

Maximum UV Index Levels in San Isidro for May

The chart shows the monthly maximum UV Index (UVI) for San Isidro 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 Isidro typically reaches 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131314131213131298
Data source: San Isidro 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 Isidro Compares to Other Months

Weather in San Isidro varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in San Isidro, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in San Isidro, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather25°C (77°F)38 mm (1.5 inches)76%very high
February Weather25°C (77°F)43 mm (1.7 inches)75%extreme
March Weather25°C (77°F)67 mm (2.6 inches)74%extreme
April Weather26°C (78°F)56 mm (2.2 inches)75%extreme
May Weather27°C (80°F)64 mm (2.5 inches)75%extreme
June Weather27°C (81°F)68 mm (2.7 inches)77%extreme
July Weather28°C (82°F)87 mm (3.4 inches)80%extreme
August Weather28°C (82°F)99 mm (3.9 inches)80%extreme
September Weather28°C (82°F)173 mm (6.8 inches)79%extreme
October Weather27°C (81°F)145 mm (5.7 inches)78%extreme
November Weather26°C (80°F)106 mm (4.2 inches)78%very high
December Weather26°C (78°F)51 mm (2.0 inches)76%very high

Compare San Isidro's Climate with Cities Worldwide