December weather forecastJember, Indonesia

Weather in December

Jember concludes the year in December with a peak in rainfall at 209mm (8.23"), distinctly marking the highest level of precipitation through the year. Accompanying this rainfall peak, the humidity levels and cloud cover find themselves on a substantial rise. The duration of sunlight noticeably drops, with daylight hours being dominated by cloudy, overcast conditions. Temperatures remain relatively stable, with marginal changes from the November readings. Furthermore, the consistent pattern of December's weather places it as the ultimate wet season month, marking a significant climatic shift in Jember, Indonesia.

Temperature

With the transition into December, Jember notes an average high-temperature of a still hot 31°C (87.8°F), closely resembling November. During December, Jember sees a mean low-temperature of 23.6°C (74.5°F).

Heat index

The heat index for December is estimated at a blistering 41°C (105.8°F). Adopt special protective actions against heat exhaustion and heat cramps. Long-duration activity risks heatstroke.
Heat index guidelines indicate values are for light wind scenarios and shaded regions. The heat index values could be amplified by up to 15 Fahrenheit (8 Celsius) degrees in direct sunlight.
Note: The heat index, also known as 'real feel' or 'feels like', is the outcome of merging air's temperature and its humidity metrics. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. 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 of high significance for children. Young people are generally more susceptible than adults because they perspire less. Furthermore, their proportionally larger skin surface to their petite bodies and the increased heat output from their actions add to the risk.
The process of perspiration is vital for the human body to get rid of excess warmth by allowing sweat to evaporate. In conditions of both high temperature and humidity (a high heat index), sweating is limited and the perception of heat is enhanced. Overheating can ensue when the body accumulates more heat than it can release, and dehydration severity may vary.

Humidity

In Jember, the average relative humidity in December is 80%.

Rainfall

In December, the rain falls for 29.3 days. Throughout December, 209mm (8.23") of precipitation is accumulated. Throughout the year, in Jember, there are 247.8 rainfall days, and 1536mm (60.47") of precipitation is accumulated.

Daylight

December has the longest days of the year in Jember, with an average of 12h and 36min of daylight.
On the first day of December, sunrise is at 04:57 and sunset at 17:31. On the last day of the month, sunrise is at 05:10 and sunset at 17:46 WIB.

Sunshine

In December, the average sunshine in Jember is 7.9h.

UV index

The months with the highest UV index are February, April through December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: An average maximum UV index of 7 in December leads to these recommendations:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Stay sun-safe with clothing that is both closely woven and worn loosely.