May weather forecast
San Juan, PR

May in San Juan heralds the arrival of the city's warmest period. The average high temperature escalates to 82.4°F (28°C), as does the sea temperature, reaching 81.5°F (27.5°C). Notably, the month has the year's maximum rainfall of 1.06" (27mm). Coincidentally, daylight and sunshine hours peak, paving the way for longer, warmer days amidst the tropical rain. The rise in warmth and precipitation establishes the onset of San Juan's summer.

Temperature

The onset of May in San Juan marks an average high-temperature of a still warm 82.4°F (28°C), hardly differing from April's 81.1°F (27.3°C). San Juan's temperature during May nights registers a minor decrease to an average low of 76.6°F (24.8°C).

Heat index

For May, the heat index is calculated to be a tropical 89.6°F (32°C). If one endures exposure and continues to be active, it might result in tiredness and heat cramps.
Note that heat index values are valued for light wind and location in the shade. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'real feel' or 'feels like', comes about by integrating the temperature readings with the humidity levels. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. It is essential to be conscious of the fact that direct sunlight can intensify the felt heat, leading to an elevation in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.

Humidity

The months with the highest humidity in San Juan are May through July, with an average relative humidity of 79%.

Rainfall

In San Juan, in May, it is raining for 14.8 days, with typically 1.06" (27mm) of accumulated precipitation. Throughout the year, there are 159.9 rainfall days, and 12.01" (305mm) of precipitation is accumulated.

Ocean temperature

In San Juan, the average seawater temperature in May is 81.5°F (27.5°C).
Note: Surface water temperatures falling between 77°F (25°C) and 84.2°F (29°C) are regarded as prime and extremely agreeable for enduring periods during any water activity.

Daylight

In May, the average length of the day in San Juan is 13h and 1min.
On the first day of the month, sunrise is at 5:56 am and sunset at 6:46 pm. On the last day of May, in San Juan, sunrise is at 5:47 am and sunset at 6:57 pm AST.

Sunshine

In May, the average sunshine in San Juan is 10.7h.

UV index

April through November, with an average maximum UV index of 7, are months with the highest UV index in San Juan. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum UV index of 7 during May leads to these instructions:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Note! Reflective surfaces like sand and water heighten the UV radiation levels.