BMKG Warns of Waves Up to 4 Metres in Indonesian Waters

Flores — The Meteorology, Climatology and Geophysical Agency (BMKG) warned of waves as high as 4 metres in several Indonesian waters from Oct. 12 to Oct. 15, 2026, with the most exposed areas stretching from waters west of Sumatra to the waters south of Java, Bali and West Nusa Tenggara.

The warning covers sea conditions that could affect fishing boats, ferries and other vessels. BMKG said waves of 2,5-4 metres were possible in parts of the Indian Ocean, while other Indonesian waters could see waves of 1,25-2,5 metres. The agency linked the conditions to strengthening winds, including winds of 6-20 knots north of the equator and 8-26 knots south of it.

Why it matters for travellers and coastal residents

For foreign visitors, the warning matters most when travel involves ferries, fishing excursions or other boat journeys in the affected waters. A forecast of up to 4 metres does not mean every route will face that height, but it signals that sea conditions may be hazardous and that departures can be affected by the weather.

BMKG identified high-wave areas including the Indian Ocean west of Aceh, the Nias, Mentawai, Bengkulu and Lampung areas, and waters south of Banten, West Java, Central Java, the Special Region of Yogyakarta, East Java, Bali and West Nusa Tenggara. The agency also warned that fishing boats face greater risk when wind speeds exceed 15 knots and waves rise above 1,25 metres.

The warning was issued through BMKG's official information on Oct. 11 and applies through Oct. 15. Reports also described moderate waves of 1,25-2,5 metres in other waters, including parts of the Malacca Strait, Java Sea, Sulawesi Sea, Maluku Sea, northern Papua waters and the Arafura Sea.

Sources

• Pos-Kupang — Indonesian regional news outlet
• Metro TV News — Indonesian news outlet
• viva.co.id
• lampung.idntimes.com
• disway.id