Several regions across Indonesia have been gripped by unusually cold temperatures over the past few days, creating a striking contrast to the typically warm summer season. Some areas have seen temperatures plummet to 10 degrees Celsius, raising questions and curiosity among locals and meteorologists alike. What could be the cause of this unexpected chill?
Circulating on social media were claims that the cold spell was due to Aphelion, a phenomenon where the Earth is farthest from the Sun. However, the Meteorology, Climatology, and Geophysics Agency (BMKG) clarified that this is not the case. According to BMKG, Aphelion has minimal impact on Earth’s atmosphere and weather patterns.
“The cold weather in Indonesia during July is not related to the Aphelion phenomenon. While Aphelion occurs when the Sun is at its farthest distance from Earth, it does not significantly affect atmospheric or surface weather conditions,” BMKG explained on their official website, Monday (July 22, 2024).
Instead, BMKG attributed the cold temperatures to natural weather patterns typical of the peak dry season, which occurs from July to September. This period is marked by winds blowing from the east and southeast, originating from Australia, which is currently experiencing winter with relatively high atmospheric pressure.
“The cold air temperatures are a natural occurrence common during the peak dry season months (July – September),” the agency stated.
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These winds bring cooler air masses over the Indian Ocean to Indonesia, particularly affecting regions south of the equator. “In addition to the impact of winds from Australia, reduced cloud cover and rainfall in areas from Java to Nusa Tenggara contribute to the cooler night temperatures. The absence of water vapor and rain means that the radiant energy released by Earth at night is not trapped in the atmosphere,” BMKG elaborated.
Moreover, clear skies allow long-wave radiation to escape into the outer atmosphere, leading to colder air near the surface, especially at night and in the early morning. “This is why the air feels colder, particularly during the night,” the agency added.
According to BMKG reports from Tuesday (July 16), Bandung experienced temperatures ranging from 19 to 30 degrees Celsius during the day, while Lembang saw cooler temperatures at 16 degrees Celsius. Kupang reported daytime temperatures around 18 degrees Celsius. In East Java, areas such as Batu, Bondowoso, Jember, and Malang had average temperatures between 15 and 26 degrees Celsius.
On the same day, Dieng in Wonosobo, Central Java, recorded daytime temperatures of 18 degrees Celsius, dropping to 10 degrees Celsius at night.
BMKG predicts that these unusually cold temperatures will persist through August, leaving residents to brace for continued chilly nights and mornings.
