December weather forecast
Toa Alta, PR

Toa Alta sees a further drop in temperature as December kicks in, marking the transition towards the cooler months. The weather becomes increasingly pleasant with a noticeable reduction in humidity levels. Rainfall exhibits a significant decline, indicating the approaching dry period, while daylight hours continue to shorten. The winds maintain a steady pace, creating a calm atmosphere. The prominent characteristic of December's weather is the lowest maximum temperature of the year, registering at 81°F (27.2°C), capstoning the year with cooler, serene weather.

Temperature

Transitioning into December, Toa Alta records an average high-temperature of a still moderately hot 81°F (27.2°C), almost identical to November's 83.1°F (28.4°C). December nights reflect a consistent temperature dip to a still warm 75.2°F (24°C), a slight descent from daytime peaks.

Heat index

December's average heat index is appraised at a tropical 86°F (30°C). Long-lasting exposure and activity potentially induce a sense of weariness, with the risk of heat cramps.
Records show heat index calculations are tailored for shaded regions and mild winds. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. The experience of temperature can be subjective, varying based on the individual's activity and heat perception, influenced by factors like wind, attire, and metabolic variations. 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 of high significance for children. Children often lack awareness of the importance of taking breaks and rehydrating. The feeling of thirst is a late indication of dehydration, so maintaining hydration, especially during long periods of physical activity, is critical.

Humidity

The average relative humidity in December is 78%.

Rainfall

In Toa Alta, in December, it is raining for 17.5 days, with typically 1.61" (41mm) of accumulated precipitation. In Toa Alta, during the entire year, the rain falls for 223.5 days and collects up to 27.95" (710mm) of precipitation.

Daylight

With an average of 11h and 0min 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 5:47 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 5:59 pm AST.

Sunshine

In Toa Alta, the average sunshine in December is 6.8h.

UV index

January through April and December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: A maximum high UV index of 6 in December translates into the following recommendations:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Stay sun-safe with clothing that is both closely woven and worn loosely.