Warning Issued for 4-Metre High Waves and Tidal Flooding in Central Java on 6 June 2026

The Indonesian Meteorological, Climatological, and Geophysical Agency (BMKG) has issued an early warning regarding the potential for high waves and tidal flooding (rob) hitting the waters of Central Java on Saturday, 6 June 2026. This natural phenomenon is reported to pose a high risk to maritime activities and the mobility of residents in coastal areas.

Usman Effendi, a forecaster at the BMKG Tanjung Emas Maritime Station in Semarang, revealed that waves in the southern waters of Central Java are expected to reach heights of 2.5 to 4 metres. Meanwhile, in the northern waters, wave heights are expected to range between 1.25 and 2.5 metres.

“Be alert to high waves in both the northern and southern waters, especially when wind speeds exceed 15 knots. These conditions are quite risky for maritime activities such as fishing boats, barges, as well as the transport of goods and passengers,” said Usman Effendi on Saturday.

In addition to high waves, the phenomenon of tidal flooding (rob) continues to threaten the North Coast (Pantura) of Central Java. BMKG predicts that the maximum tidal height could reach 1 metre, occurring between 10:00 and 16:00 WIB.

This condition has been reported to begin disrupting the economic activities of local residents, ranging from transport disruptions and the loading/unloading process of goods at ports, to the inland aquaculture and salt farming sectors.

Although Central Java is entering the dry season, the potential for light to moderate rain is still monitored in several areas. Agus Triyono, a forecaster at the BMKG Ahmad Yani Meteorological Station in Semarang, urged the public to remain vigilant against sudden weather changes. Areas likely to experience light to moderate rain include Purbalingga, Banjarnegara, Karanganyar, Bumiayu, and Majenang, while light rain is predicted for Cilacap, Banyumas, Wonosobo, Mungkid, Temanggung, Kajen, Pemalang, Slawi, Brebes, and Magelang.

“Winds are blowing from the east to the south at speeds of 3-27 kilometres per hour. Air temperatures range between 18-34 degrees Celsius with humidity levels between 50-95 per cent,” concluded Agus.