BMKG Reveals the Cause of the Hour-long Rain that Drenched Jakarta and Its Surroundings

JAKARTA - Heavy rain has hit the Jakarta area and the buffer area since Monday morning, triggering flooding and flooding at a number of points. The Meteorology, Climatology and Geophysics Agency explained the cause of the extreme weather.

Rainfall began to increase since Monday, January 12 morning, and lasted for hours until noon. This condition has a wide impact in Jakarta, Bogor, Depok, Tangerang, and Bekasi.

In Jakarta, puddles were observed in several residential areas and activity centers, including Kelapa Gading, Sunter, Pademangan, and Mangga Dua. Similar situations occurred in a number of areas in Bekasi, Bogor, and Tangerang.

The water that flooded the road caused traffic to slow down. A number of public transportation services were also affected, including adjustments to Transjakarta operations and disruption of KRL travel on the Angke-Kampung Bandan line due to flooded tracks.

BMKG noted that heavy rain not only occurred in Jabodetabek. In the last 24 hours, heavy rain also spread to other areas in Indonesia, ranging from Banten to Nusa Tenggara.

The Head of the BMKG Weather Early Prediction and Warning Team, Ida Pramuwardani, said that several areas recorded rainfall of more than 100 millimeters per day, including West Java, Bali, and East Nusa Tenggara.

According to BMKG, this condition is triggered by a combination of regional atmospheric dynamics. One of them is the strengthening of wind flow from the South China Sea which moves south through the Karimata Strait to Java Island.

The wind pattern forms an air mass meeting zone in the Java, Bali, and West Nusa Tenggara regions, thus supporting the growth of high-intensity rain clouds.

Another factor comes from the low pressure system in the eastern Australian region. This system affects the wind circulation in southern Indonesia and strengthens the slowing air flow.

"This situation encourages the process of continuous air rise, which increases the chance of heavy rain," said Ida, Tuesday, January 13.

BMKG predicts that the potential for heavy rain will continue for the next week, namely in the period from January 12-18, 2026. In addition to Java and Nusa Tenggara, the Sulawesi region to Papua is also potentially affected.

BMKG urges local governments and the public to increase vigilance against the risk of flooding, landslides, and transportation disruptions during periods of extreme weather.

Regarding the rainy season, BMKG assessed that the peak in general is still in January to February 2026. However, in some areas such as Java and Sulawesi, the peak of the rainy season is expected to come earlier than the previous estimate.

On the other hand, the regions of Sumatra and Bali actually experienced a shift in the peak of the rainy season to a slower period compared to normal conditions.