Thunderstorms and heavy rainfall are forecasted to occur starting from 09 December 2025, 18:30 WIB in parts of Sumatera Utara especially in: Adian Koting, Aek Songsongan, Afulu, Air Batu, Alasa, Alasa Talumuzoi, Amandraya, Andam Dewi, Angkola Barat, Angkola Sangkunur, Angkola Selatan, Angkola Timur, Aramo, Arse, Badiri, Bahorok, Baktiraja, Balige, Bandar Pulau, Barus, Barus Utara, Batahan, Batang Angkola, Batang Kuis, Batang Natal, Batang Onang, Batang Serangan, Batang Toru, Bawolato, Berampu, Binjai, Binjai Barat, Binjai Kota, Binjai Selatan, Binjai Timur, Binjai Utara, Borbor, Boronadu, Botomuzoi, Bukit Malintang, Buntu Pane, Dolok Pardamean, Dolok Sanggul, Dolok Silau, Fanayama, Garoga, Gebang, Gido, Gomo, Gunung Sitember, Gunungsitoli Idanoi, Hamparan Perak, Harian, Hibala, Hilimegai, Hilisalawa'Ahe, Hiliserangkai, Hinai, Hulu Sihapas, Huruna, Huta Bargot, Idanogawo, Idanotae, Juhar, Kerajaan, Kolang, Kuala, Kutalimbaru, Kutambaru, Labuhan Deli, Lae Parira, Laguboti, Lahewa, Lahewa Timur, Lahomi, Lahusa, Lingga Bayu, Lintong Nihuta, Lolofitu Moi, Lolomatua, Lolowau, Lotu, Luahagundre Maniamolo, Lumut, Ma'U, Mandrehe, Mandrehe Barat, Mandrehe Utara, Maniamolo, Marancar, Mazino, Mazo, Medan Area, Medan Barat, Medan Baru, Medan Deli, Medan Denai, Medan Helvetia, Medan Kota, Medan Labuhan, Medan Maimun, Medan Marelan, Medan Perjuangan, Medan Petisah, Medan Polonia, Medan Selayang, Medan Sunggal, Medan Tembung, Medan Timur, Merek, Moro'O, Muara, Muara Batang Gadis, Muara Batang Toru, Munte, Naga Juang, Nainggolan, Namohalu Esiwa, Natal, O'O'U, Onan Ganjang, Onohazumba, Onolalu, Padang Bolak Julu, Padang Tualang, Padangsidimpuan Angkola Julu, Padangsidimpuan Batunadua, Padangsidimpuan Hutaimbaru, Padangsidimpuan Selatan, Padangsidimpuan Tenggara, Padangsidimpuan Utara, Pagaran, Pagindar, Pahae Jae, Pahae Julu, Pakkat, Palipi, Pandan, Pangaribuan, Pangururan, Pantai Labu, Panyabungan Barat, Panyabungan Utara, Paranginan, Parbuluan, Parlilitan, Parmonangan, Pasaribu Tobing, Pegagan Hilir, Pematang Sidamanik, Percut Sei Tuan, Pergetteng Getteng Sengkut, Pinangsori, Pintu Pohan Meranti, Pollung, Pulau-Pulau Batu, Pulau-Pulau Batu Barat, Pulau-Pulau Batu Timur, Pulau-Pulau Batu Utara, Purba Tua, Rahunig, Ranto Baek, Raya, Raya Kahean, Saipar Dolok Hole, Salak, Salapian, Sarudik, Sawit Seberang, Sayur Matinggi, Secanggang, Sei Bingei, Selesai, Siabu, Sianjar Mula Mula, Siatas Barita, Sibabangun, Sibolangit, Sibolga Kota, Sibolga Sambas, Sibolga Selatan, Sibolga Utara, Siborong-Borong, Sidikalang, Sidua'Ori, Siempat Nempu, Siempat Nempu Hilir, Siempat Nempu Hulu, Siempat Rube, Sijamapolang, Silahisabungan, Silima Pungga Pungga, Silinda, Silou Kahean, Simangumban, Sinunukan, Sipahutar, Sipirok, Sipispis, Sipoholon, Sirandorung, Sirapit, Sirombu, Sitahuis, Sitelu Tali Urang Jehe, Sitelu Tali Urang Julu, Sitinjo, Sitio-Tio, Sogae'Adu, Somambawa, Somolo-Molo, Sorkam, Sorkam Barat, Sosopan, Sosor Gadong, Stabat, Stm Hulu, Suka Bangun, Sumbul, Sunggal, Susua, Tampahan, Tanah Masa, Tanah Pinem, Tano Tombangan Angkola, Tapian Nauli, Tarabintang, Tarutung, Teluk Dalam, Tigalingga, Tinada, Tinggi Raja, Toma, Tugala Oyo, Tukka, Ulu Idanotae, Ulu Moro'O, Ulugawo, Ulunoyo, Ulususua, Umbunasi, Wampu. These conditions may lead to reduced visibility, strong winds, and localized flooding. The public is strongly advised to remain vigilant during this period, limit outdoor activities, and take all necessary precautions to ensure safety. Conditions are expected to gradually improve by 09 December 2025, 21:30 WIB.