December weather forecast
Juana Díaz, PR

December rounds off the year in Puerto Rico, USA, with a noticeable coolness in the air. Despite the slight dip in temperatures, the month remains highly pleasant, making it an ideal time for exploring the city. December marks this slight drop in sea temperatures after a remarkably warm and moist November. Both rainfall and sunshine hours see a reduction compared to the previous month, delivering a calming close to the year. As December gives way to January, one can eagerly anticipate more sunlight hours and a slightly warmer climate.

Temperature

As November transitions into December, the average high-temperature in Juana Díaz, Puerto Rico, rests at a still warm 82°F (27.8°C), maintaining a close resemblance to the previous month. During the nights in December, Juana Díaz experiences a consistent average temperature of 72.7°F (22.6°C).

Heat index

For most parts of December, the heat index is estimated at a tropical 87.8°F (31°C). Persisting in activity during long-term exposure might induce weariness, with subsequent heat cramps.
Bear in mind that the heat index values are determined for shaded areas and light breezes. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.

Humidity

In December, the average relative humidity is 79%.

Rainfall

In Juana Díaz, during December, the rain falls for 18.6 days and regularly aggregates up to 1.42" (36mm) of precipitation. In Juana Díaz, during the entire year, the rain falls for 249.1 days and collects up to 28.82" (732mm) of precipitation.

Ocean temperature

In December, the average ocean temperature in Juana Díaz is 82°F (27.8°C).
Note: For any water activity, the surface water temperatures in the range of 77°F (25°C) to 84.2°F (29°C) are deemed excellent and incredibly pleasant for longer durations.

Daylight

With an average of 11h and 6min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 6:41 am and sunset at 5:49 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:01 pm AST.

Sunshine

In Juana Díaz, the average sunshine in December is 7h.

UV index

The months with the lowest UV index in Juana Díaz, Puerto Rico, are January through April, November and December, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for average individuals.
Note: The daily high UV index of 6 during December translates into the following recommendations:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. UV radiation from the sun is at its strongest between 10 a.m. and 4 p.m. Try to limit direct exposure during these hours. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Stay aware! UV radiation is magnified when reflecting off sand and water.