December weather forecast
Puerto Rico, Bolivia

December, the first month of the summer in Puerto Rico, is still a hot month, with an average temperature varying between 22.3°C (72.1°F) and 30.1°C (86.2°F).

Temperature

Puerto Rico's weather in December indicates an average high-temperature of a still tropical 30.1°C (86.2°F), nearly consistent with the 32.2°C (90°F) of November. Puerto Rico, in December, witnesses an average low-temperature of 22.3°C (72.1°F).

Heat index

December's mean heat index is computed to be a blistering 40°C (104°F). Adopt special protective actions against heat exhaustion and heat cramps. Long-duration activity risks heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunshine, the heat index could climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', unifies temperature and humidity readings to offer a comprehensive feel of warmth. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young individuals are generally in more danger than adults due to their lower capacity to sweat. Moreover, their large skin surface in relation to their small bodies and the increased heat generation from their activities makes them more vulnerable.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. When relative humidity increases, the body's capacity to evaporate heat decreases, leading to a heightened sense of warmth. As the body accumulates more heat than it can release, body temperature goes up, increasing the risk of heat-related health issues.

Humidity

In Puerto Rico, the average relative humidity in December is 87%.

Rainfall

In Puerto Rico, in December, during 26.4 rainfall days, 180mm (7.09") of precipitation is typically accumulated. Throughout the year, there are 233.4 rainfall days, and 1251mm (49.25") of precipitation is accumulated.

Daylight

December has the longest days of the year, with an average of 12h and 48min of daylight.
On the first day of the month, sunrise is at 05:57 and sunset at 18:41. On the last day of December, in Puerto Rico, sunrise is at 06:10 and sunset at 18:56 -04.

Sunshine

The average sunshine in December is 6.2h.

UV index

January through June and December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the average person.
Note: A daily high UV index of 6 in December leads to these guidelines:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.