The Meteorology, Climatology, and Geophysics Agency (BMKG) has predicted that the extreme heat currently affecting several regions in Indonesia, reaching a maximum temperature of 37.6°C, will continue until the end of October or early November 2025. Areas such as Kalimantan, Papua, Java, West Nusa Tenggara (NTB), and East Nusa Tenggara (NTT) are experiencing intense heat, primarily caused by the apparent movement of the sun south of the equator.
Responding to this phenomenon, Professor Djati Mardiatno, Head of the Center for Environmental Studies at Universitas Gadjah Mada (PSLH UGM), explained that the current hot weather results from a combination of the sun’s apparent motion, eastern monsoon winds, and local factors such as the urban heat island effect.
“Areas with dense building structures, especially urban centers, tend to experience higher temperatures. Land conversion and the increasing number of buildings have contributed to this extreme heat,” he said on Friday, Oct. 24, 2025.
According to Professor Mardiatno, this kind of hot weather is a periodic natural phenomenon that occurs annually.
However, in recent years, the heat has felt more extreme.
As a result, more people rely on air conditioners (AC) and fans to cool indoor spaces.
Yet, he noted, air conditioners also contribute to additional heat emissions.
“When more people use air conditioners, the warm air released outdoors also increases the overall temperature,” he explained.
Although Indonesia has entered the rainy season, many areas still experience high temperatures.
This is due to solar radiation reflecting off the Earth’s surface.
When clouds are present, the reflected heat can be trapped and redirected back toward the ground, intensifying the heat sensation.
To mitigate these effects, Professor Mardiatno emphasized that reducing heat cannot be achieved instantly but requires long-term environmental planning.
One effective strategy is to expand green open spaces and increase tree coverage in urban and residential areas.
“Trees and green cover can help absorb heat and provide a cooler microclimate,” he said.
As a practical measure, he advised the public to maintain their physical health and avoid outdoor activities during the peak heat hours, between 10 a.m. and 2 p.m., unless absolutely necessary.
“If you must go outside, protect your body from direct sunlight to prevent adverse health effects,” he concluded.
Author: Jesi
Editor: Gusti Grehenson
Post-editor: Lintang Andwyna
Illustration: Freepik