Central Java Weather Forecast: Warning of 4-Metre Waves and Coastal Flooding

The Meteorology, Climatology and Geophysics Agency (BMKG) forecasts that weather in the Central Java region will be dominated by clear to cloudy skies throughout the day on Tuesday (11/8). Despite the absence of rain, the public is urged to be wary of the threat of high waves reaching up to four metres in southern waters, tidal flooding along the Pantura route, and the risk of drought.

BMKG forecaster at the Ahmad Yani Meteorological Station in Semarang, Winda Ratri, stated that air temperatures will range between 16 and 34 degrees Celsius with humidity levels of 45 to 95 percent. Winds are expected to blow from the east to the south at speeds of 5 to 35 km/h. The temperature difference will be particularly noticeable in mountainous and highland areas, where the weather will feel very cold at night and scorching hot during the day.

This rainless condition is also accelerating the depletion of water sources such as wells, lakes, reservoirs, rivers, and small dams, triggering clean water shortages in dozens of areas across Central Java. “Ahead of the peak of the dry season, be vigilant against forest and land fires, as many plants are dry and easily ignited,” Winda advised.

Meanwhile, maritime hazards threaten coastal areas. BMKG forecaster at the Tanjung Emas Maritime Station in Semarang, Wahyu Mulyani, explained that high waves of 2.5 to 4 metres are likely to occur in the southern waters of Central Java. These conditions pose a significant risk to shipping activities, including fishing boats, barges, and passenger vessels, especially when wind speeds exceed 15 knots. In the northern waters, particularly around Karimunjawa, waves are expected to reach heights of 1.25 to 2.5 metres. A tidal flood phenomenon is also forecast between 5 a.m. and 9 a.m. WIB, with a maximum height of 1 metre, which could trigger flooding along the Pantura coast.

“Be alert for high waves and tidal flooding in several areas such as Pekalongan, Batang, Kendal, Semarang, Demak, Jepara, Pati, and Rembang, as it will disrupt residents’ activities,” Wahyu stated. Overall, the weather in Central Java’s waters is expected to be clear to cloudy, with wind patterns blowing from the northeast to the southeast at speeds of 2 to 20 knots. High waves of 1.25 to 2.5 metres are still likely to occur in Karimunjawa.