Heavy rain lashed the Special Region of Yogyakarta (DIY) from Friday to Saturday (December 26-27, 2025), driven by Tropical Cyclone Grant, Cyclone 96S, and a Rossby wave. The downpours caused floods, landslides, and infrastructure damage across several districts, with the Meteorology, Climatology, and Geophysics Agency (BMKG) warning of similar conditions in the coming days.
The BMKG Yogyakarta station attributed the extreme rainfall in DIY from Friday afternoon (December 26, 2025) to Saturday morning (December 27, 2025) to multiple atmospheric disturbances. Station head Warjono identified Tropical Cyclone Grant southwest of Sumatra, seed Cyclone 96S south of West Nusa Tenggara, and a Rossby wave near Java as key triggers.
"These conditions formed a wind shearline and convergence, fostering rain cloud development over DIY," Warjono said on Sunday (December 28, 2025). High humidity fueled massive convective clouds, leading to intense rain with lightning, thunder, and gusty winds.
Impacts included 104 damage points in Bantul Regency across 10 sub-districts (87 fallen trees, 30 damaged houses, 12 landslides), with Rp 2.7 million in losses and evacuations in Sanden Sub-district due to flooding. Gunungkidul Regency reported 16 points in seven sub-districts (Rp 8.9 million losses), and Kulon Progo had 10 points (Rp 40 million losses). No incidents were reported in Sleman Regency or Yogyakarta City.
DIY BPBD Operations Head Agustinus Ruruh Haryata said response and assessment efforts continue. BMKG forecasts moderate to heavy rain with lightning and strong winds possible in DIY during late afternoons and evenings over the next 2-3 days.
