December weather forecast
Arroyo, PR

December in Arroyo brings the year to a comfortable close, with mild temperatures and a significant reduction in rainfall to 1.61" (41mm). The cooler nights and warm sunny days mark the onset of the holiday season. Despite shorter days, the consistently moderate sea temperature ensures the continued enjoyment of aquatic activities. December's weather sets the ideal backdrop for spending time outdoors, whether it's celebrating festivities or soaking in the natural beauty of the region. The steady wind keeps the climate comfortable, rounding off an eventful meteorological year in Arroyo, Puerto Rico.

Temperature

Arroyo, Puerto Rico, greets December with an average high-temperature of a still warm 80.8°F (27.1°C), marking a slight deviation from the preceding month. Registering an almost steady temperature, Arroyo's nights in December see an average low of 72.9°F (22.7°C).

Heat index

During December, the heat index is calculated to be a tropical 86°F (30°C). If exposure and activity persist, fatigue could ensue, possibly leading to heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. In the presence of direct sunshine, the heat index could be augmented by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an aggregate value of air's warmth and moisture to show the human-felt temperature. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.

Humidity

In Arroyo, the average relative humidity in December is 80%.

Rainfall

In Arroyo, Puerto Rico, during December, the rain falls for 18.9 days and regularly aggregates up to 1.61" (41mm) of precipitation. In Arroyo, during the entire year, the rain falls for 255.3 days and collects up to 29.41" (747mm) of precipitation.

Ocean temperature

In Arroyo, the average seawater temperature in December is 82°F (27.8°C).
Note: For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

With an average of 11h and 6min of daylight, December has the shortest days of the year.
On the first day of December in Arroyo, sunrise is at 6:39 am and sunset at 5:47 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 5:59 pm AST.

Sunshine

With an average of 6.5h of sunshine, December has the least sunshine of the year in Arroyo.

UV index

The months with the lowest UV index are January through April, November and December, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for the average person.
Note: The maximum UV index, 6 during December, leads to the following recommendations:
Deflect overexposure. Sun protection is a necessity. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. Opt for tightly woven and loose clothing to enhance protection from the Sun. Attention! The reflection of both water and sand can increase the intensity of UV rays.