Why Is Jakarta Still Hot While Bogor Is Already Getting Rain? An Expert Explains

JAKARTA — Hot weather is still being felt in Jakarta in October, even though several surrounding areas, including Bogor, have started to see rain. The difference in weather conditions is influenced by several factors, from the sun’s position and the characteristics of urban areas to atmospheric conditions and topography.

Sonni Setiawan, an expert in geophysics and meteorology at IPB University, said that the sun being directly above Java at certain times in October is one factor contributing to higher surface temperatures. Solar radiation reaching the Earth’s surface can raise temperatures, particularly when cloud cover is insufficient to block the sunlight.

“Shortwave radiation from the sun received by the surface can increase surface temperatures, especially when cloud cover is not sufficient to block that radiation,” Sonni said in a written statement, quoted on Friday (23 October 2026).

Why is Jakarta hotter? Sonni explained that changes in urban land cover affect the ability of surfaces to absorb and store heat. The prevalence of buildings and paved roads can intensify surface warming caused by solar radiation.

“These conditions also increase the longwave radiation re-emitted by the Earth’s surface,” Sonni said.

In addition, water vapour and air pollution affect the absorption of longwave radiation from the Earth’s surface, trapping heat in the atmosphere. This process is associated with the greenhouse effect, which can raise air temperatures.

“High exposure to sunlight, land-cover characteristics and atmospheric conditions make Jakarta hotter, particularly when cloud cover is not yet sufficient to block solar radiation,” he said.