December weather forecast
Jakarta, Indonesia

The first month of the summer, December, is still a hot month in Jakarta, Indonesia, with an average temperature varying between 30.6°C (87.1°F) and 26°C (78.8°F).

Temperature

In Jakarta, the average high-temperature in December is almost the same as in November - a still tropical 30.6°C (87.1°F). In December, in Jakarta, the average low-temperature is 26°C (78.8°F).

Heat index

In December, the average heat index is appraised at a very hot 37°C (98.6°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'feels like', or 'felt air temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like wind, pregnancy, clothing, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

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

Rainfall

In Jakarta, during 23.9 rainfall days, 123mm (4.84") of precipitation is typically accumulated. In Jakarta, during the entire year, the rain falls for 252 days and collects up to 1150mm (45.28") of precipitation.

Sea temperature

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

Daylight

With an average of 12h and 29min of daylight, December has the longest days of the year.
On the first day of the month, sunrise is at 05:27 and sunset at 17:55. On the last day of December, in Jakarta, Indonesia, sunrise is at 05:41 and sunset at 18:09 WIB.

Sunshine

In December, the average sunshine in Jakarta, Indonesia, is 9.3h.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index. January through December, with an average maximum UV index of 7, are months with the lowest UV index in Jakarta. A UV Index value of 6 to 7 symbolizes a high health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In December, the average maximum UV index of 7 translate into the following recommendations:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.