BMKG warns of 4-metre waves south of Bali through Oct. 4

Denpasar — The Balai Besar Meteorologi Klimatologi dan Geofisika, or BMKG’s regional meteorology, climatology and geophysics office, has warned of waves measuring 2,5–4 metres in the southern Bali Indian Ocean from Oct. 1 through Oct. 4, 2026. The warning applies to marine conditions that can affect fishing boats, barges and ferries.

The warning covers several waters around Indonesia, including the southern Bali Indian Ocean. BMKG’s stated thresholds identify risks for fishing boats when winds reach 15 knots and waves reach 1,25 metres, for barges at 16 knots and 1,5-metre waves, and for ferries at 21 knots and 2,5-metre waves.

Why the warning matters to Bali visitors

For foreign visitors and residents, the warning concerns activities and transport on the sea rather than conditions across the island. Marine-tourism operators and the public are urged to remain alert as elevated waves may affect coastal excursions, fishing activity and ferry operations in exposed waters. The reports do not state that beaches, ports or ferry services have been closed.

Media Indonesia reported that the Head of BMKG Region III Denpasar, Cahyo Nugroho, urged the public, fishers and marine-tourism operators to watch for high waves above two metres. The report also said waves in southern Bali waters could reach 3,5 metres on Thursday, Oct. 1, and that elevated conditions could continue through Sunday, Oct. 4.

BMKG’s warning is valid through Oct. 4, 2026. The reports identify the southern Bali Indian Ocean as the relevant area and specify the marine users whose vessels may face risks under the stated wind and wave conditions.

Sources

• IDN Times Bali — regional news organisation
• RRI — public radio news organisation
• balipost.com
• maritim.bmkg.go.id