BMKG Explains Cause of Sudden Heavy Rain in Bogor Amid Dry Season

The Meteorology, Climatology, and Geophysics Agency (BMKG) has explained the cause of the heavy rain that fell on the Bogor area on Saturday night after a prolonged dry spell. BMKG Secretary Principal Guswanto stated that the downpour was triggered by regional atmospheric phenomena, including the Madden-Julian Oscillation (MJO), Kelvin waves, and Equatorial Rossby waves. These disturbances encouraged the growth of rain clouds despite West Java currently being in the dry season. “This phenomenon is temporary and does not signal the end of the dry season,” Guswanto said on Sunday (19/7/2026). BMKG noted that all of West Java has been in the dry season since early July 2026, with average rainfall below 50 mm per ten-day period. Guswanto added that the El Niño phenomenon persists in the Pacific Ocean with a Nino 3.4 index of +1.25, reinforcing the trend of reduced rainfall across Indonesia, including West Java. However, he emphasised that localised rain can still occur due to regional atmospheric dynamics. The rain in the Cibinong area lasted approximately 1.5 hours after days of dry weather, and residents welcomed it as it helped alleviate the drought and clean water crisis. Guswanto stressed that the rain does not mark the end of the dry season. He noted that sporadic rain is still possible in West Java until the end of July, but overall rainfall remains low. Residents are urged to remain vigilant regarding drought conditions, as water distribution remains a primary need in 13 affected sub-districts.