December weather forecast
Jakarta, Indonesia

December in Jakarta is dominantly characterized by the wet season, with substantial rainfall readings of 123mm (4.84"). This rise in rain levels from November to December ushers in a slightly cooler, yet humid weather. Throughout the month, the city experiences abundant rainfall, high humidity, and cloud coverage of 43%. Notwithstanding these conditions, the stable sea temperature of 29°C (84.2°F) and a UV index of 7 provide an inviting scenario for beach outings. With calm wind conditions averaging around 10.8km/h (6.7mph), this month holds a serene atmosphere aside from the typical intermittent rain showers.

Temperature

December's advent in Jakarta, Indonesia, notes a subtle adjustment in average high-temperature to a still hot 30.6°C (87.1°F) from November. During the December nights, Jakarta's temperature maintains an average close to the daytime highs, settling at a moderately hot 26°C (78.8°F).

Heat index

December's heat index is calculated to be a very hot 37°C (98.6°F). Implement additional safety measures to avoid heat cramps and heat exhaustion. Persistent activity might trigger heatstroke.
Note that heat index values are valued for light wind and location in the shade. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Keep aware, the sun, when shining directly, can intensify the heat experience, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Younglings frequently fail to recognize the requirement to rest and rehydrate. Thirst emerges late in dehydration - it is imperative to keep hydration levels high, particularly during extended physical exertions.
Perspiration and the resultant sweat evaporation are the body's natural thermostat, helping regulate temperature. Under conditions of high relative humidity, the rate of evaporation decreases. This results in the body retaining more heat than under conditions of dry air. Excessive heat that's not properly managed leads to increased body temperatures and resultant health issues.

Humidity

In Jakarta, the average relative humidity in December is 71%.

Rainfall

In Jakarta, in December, during 23.9 rainfall days, 123mm (4.84") of precipitation is typically accumulated. Throughout the year, in Jakarta, there are 252 rainfall days, and 1150mm (45.28") of precipitation is accumulated.

Sea temperature

In December, the average sea temperature is 29°C (84.2°F).
Note: For swimming, diving, and various water activities, the temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are seen as highly enjoyable and comfortable for extended durations without any discomfort.

Daylight

With an average of 12h and 30min of daylight, December has the longest days of the year.
On the first day of December, sunrise is at 05:27 and sunset at 17:55. On the last day of the month, sunrise is at 05:41 and sunset at 18:10 WIB.

Sunshine

In December, the average sunshine is 9.3h.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index in Jakarta. The months with the lowest UV index are January through December, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for the average person.
Note: In December, the maximum UV index of 7 translates into these guidelines:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Remember that UV radiation from the Sun is strongest between 10 a.m. and 4 p.m. Make an effort to limit direct sun exposure during this time. During bright days, sunglasses that offer UVA and UVB defense are recommended. Warning! Sand and water reflections boost the intensity of UV exposure.