BMKG: Rain Potential Persists Outside Java Amid Dominant Dry Conditions

The Meteorology, Climatology and Geophysics Agency (BMKG) predicts that the majority of Indonesia will still experience low rainfall over the coming week. This condition is influenced by global climate factors that tend to reduce rain cloud formation in the Indonesian region. “In the coming week, weather conditions in Indonesia are generally predicted to still be dominated by low rainfall,” said BMKG’s Acting Deputy for Meteorology, Andri Ramdhani.

During the second ten-day period of July 2026, approximately 91.45 percent of Indonesia’s territory is predicted to experience low rainfall, while 8.52 percent is in the medium category and only 0.03 percent is in the high category. Andri explained that the weekly relative Niño 3.4 Index still shows a value of +1.52, with a 30-day running average of the Southern Oscillation Index (SOI) at -27.4. These indices have shown significance since mid-May and are predicted to reach a strong El Niño level in 2026.

Despite global phenomena indicating minimal potential for rain cloud formation, the spatial Madden-Julian Oscillation (a large-scale atmospheric wave phenomenon) is predicted to be active over Riau, Riau Islands, West Kalimantan, East Kalimantan, and North Kalimantan, potentially increasing rainfall in these areas. Additionally, Kelvin and Equatorial Rossby waves are forecast to be active over North Kalimantan, East Kalimantan, Central Sulawesi, Gorontalo, North Sulawesi, North Maluku, and the Pacific Ocean north of Papua. “Supported by the potential for wind convergence and relatively warm sea surface temperatures, the potential for rain cloud formation in parts of Indonesia still exists,” Andri stated. The BMKG has therefore advised the public to remain alert for moderate intensity rain occurring in Aceh, North Sumatra, West Sumatra, Riau, Riau Islands, South Sumatra, Bengkulu, West Kalimantan, East Kalimantan, North Kalimantan, Central Sulawesi, West Sulawesi, South Sulawesi, Southeast Sulawesi, Papua Highlands, and Papua.