December weather forecast
Semarang, Indonesia

December in Semarang marks the peak of the rainy season, rain makes a strong presence throughout the month and humidity levels remain high. The year closes in with maximum rainfall amounts of 356mm (14.02"), spanning almost every day of the month. Meanwhile, the sea temperature hits its apex, making it excellent for aquatic activities. Despite the humidity, December's days are relatively cool, with temperatures becoming slightly chillier than the annual average. The pattern of increased cloud cover persists, leading to the least amount of sunshine hours for the year.

Temperature

December's onset in Semarang sees an average high-temperature of a still moderately hot 27°C (80.6°F), exhibiting a slight fluctuation from the previous month. An average low-temperature of 21.6°C (70.9°F) is observed during December nights.

Heat index

For December, the heat index is estimated at a hot 30°C (86°F). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.
One should be cognizant that the heat index values are tailored for shaded spots and mild winds. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', comes about by integrating the temperature readings with the humidity levels. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Do note, being directly under sun rays can amplify the heat you feel, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.

Humidity

In December, the average relative humidity is 85%.

Rainfall

In Semarang, in December, during 28.5 rainfall days, 356mm (14.02") of precipitation is typically accumulated. In Semarang, Indonesia, during the entire year, the rain falls for 305 days and collects up to 2988mm (117.64") of precipitation.

Sea temperature

With an average sea temperature of 30.3°C (86.5°F), December is the month with the warmest seawater in Semarang.
Note: When the water's temperature hits more than 30°C (86°F), it arguably becomes less enjoyable for cooling down.

Daylight

The month with the longest days in Semarang is December, with an average of 12h and 30min of daylight.
On the first day of the month, sunrise is at 05:12 and sunset at 17:42. On the last day of December, in Semarang, sunrise is at 05:25 and sunset at 17:57 WIB.

Sunshine

The month with the least sunshine in Semarang, Indonesia, is December, with an average of 6.7h of sunshine.

UV index

January through December, with an average maximum UV index of 6, are months with the highest UV index. January through December, with an average maximum UV index of 6, are months with the lowest UV index in Semarang. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The daily high UV index of 6 during December translates into the following recommendations:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.