BMKG Warns of Potential Tidal Flooding in Several Areas in Indonesia on October 21

TEMPO.CO, Jakarta - Indonesia's Meteorology, Climatology, and Geophysics Agency (BMKG) has mentioned the occurrence of the new moon phase on October 21, 2025, which could potentially increase the maximum sea level, leading to coastal flooding or tidal flooding.

The Maritime Meteorology Director of BMKG, Eko Prasetyo, stated that based on surface water observations and tidal predictions, coastal flooding or tidal flooding is likely to occur in several coastal regions of Indonesia.

He mentioned, "Among the affected areas are the coastal regions of North Sumatra, Bangka Belitung Islands, Lampung, Banten, Jakarta, West Java, Central Java, East Java, Bali, East Nusa Tenggara, North Kalimantan, Central Kalimantan, South Kalimantan, North Sulawesi, and Maluku," in a statement released on Sunday, October 19, 2025.

According to him, the potential coastal flooding in general could impact the activities of communities around ports and coastal areas, such as loading and unloading activities at ports, activities in coastal settlements, as well as saltpond and inland fisheries activities. He advised the public to remain vigilant and alert in order to anticipate the impact of the maximum sea level and to pay attention to maritime weather updates from the BMKG.

Locations and Timings

The potential locations and timings for coastal flooding are as follows.

1. North Sumatra Coastal Regions, October 19-26, 2025
- Medan Belawan Coast
- Medan Labuhan Coast
- Medan Marlan Coast

2. Bangka Belitung Islands Coastal Regions, October 17, 2025, and October 24-31, 2025
- Bangka Coast, Belitung Coast

3. Lampung Coastal Regions, October 23-26, 2025
- Tanggamus Coast
- East Lampung Coast
- South Lampung Coast
- Pesawaran Coast

4. Banten Coastal Regions, October 24-28, 2025
- North Tangerang Coast, October 22-25, 2025
- West Sunda Strait, Pandeglang
- South Pandeglang Coast, October 20-27, 2025
- Southern Waters of Lebak

5. Jakarta Coastal Regions, October 22-28, 2025
- Kamal Muara Coast
- Kapuk Muara Coast
- Pluit Coast
- Ancol Coast
- Kamal Coast
- Marunda Coast
- Cilincing Coast
- Tanjung Priok Coast
- Kalibaru Coast
- Muara Angke Coast, Penjaringan

6. West Java Coastal Regions, October 17, 2025, and October 31-November 04, 2025
- North Coastal Region of West Java (Subang, Indramayu & Cirebon), October 21-27, 2025
- South Coastal Region of West Java (Sukabumi, Garut, Cianjur, Tasikmalaya & Pangandaran)

7. Central Java Coastal Regions, October 17-18, 2025, and October 27-31, 2025
- Semarang City Coast, Demak Regency, Pekalongan Regency, and Pekalongan City, October 17-20, 2025
- Brebes Regency Coast, October 26-31, 2025
- Tegal City Coast, Tegal Regency, and Pemalang Regency

8. East Java Coastal Regions, October 24-26, 2025
- North Surabaya Coast
- Tuban Coast
- Benowo Coast
- Gresik Coast
- Lamongan Coast

9. Bali Coastal Regions, October 21-25, 2025
- South Bali Coast

10. East Nusa Tenggara Coastal Regions, October 18-21, 2025
- Flores Island - Alor Coast
- Sabu Island - Raijua Coast
- Timor Island - Rote Coast
- Sumba Island Coast

11. North Kalimantan Coastal Regions, October 21-25, 2025
- Waters of Tarakan
- Waters of Tanjung Selor
- Waters of Nunukan - Sebatik

12. Central Kalimantan Coastal Regions, October 17-19, 2025, and October 28-31, 2025
- South Coast of West Kotawaringin (Keraya, Kubu, Kumai)

13. South Kalimantan Coastal Regions, October 17-19, 2025, and October 26-30, 2025
- Barito Kuala Coast, Banjar, Banjarmasin, Tanah Laut, October 21-28, 2025
- Kotabaru Coast, Tanah Bumbu

14. North Sulawesi Coastal Regions, October 22-25, 2025
- East Bolaang Mongondow Coast
- South Bolaang Mongondow Coast
- Southeast Minahasa Coast
- Old Manado Coast
- Manado Coast
- Bitung Coast
- Talaud Islands Coast, October 22-26, 2025
- Sangihe Islands Coast

15. Maluku Coastal Regions, October 22-29, 2025
- Ambon Coast
- Central Maluku Coast, October 20-29, 2025
- East Seram Coast
- Aru Islands Coast, October 21-29, 2025
- Kei Islands Coast, October 20-30, 2025
- Tanimbar Islands Coast

Editor’s Choice: Jakarta Moves to Mitigate Extreme Heat

Click here to get the latest news updates from Tempo on Google News