Dry Season Expands, Nearly Half of Indonesia Now in Drought
The Meteorology, Climatology and Geophysics Agency (BMKG) has stated that the dry season is continuing to expand across Indonesia. As of early July 2026, a total of 342 seasonal zones, or approximately 48.9 per cent of the country’s territory, have entered the dry season.
In its weather outlook for the period of 7–13 July 2026, the BMKG explained that the widening dry season is influenced by the persistence of the El Niño phenomenon in the Pacific Ocean. This condition is indicated by a Niño 3.4 index of +1.24 and a Southern Oscillation Index (SOI) of -23.3, which generally contribute to reduced rainfall potential across most of Indonesia.
“As the dry season expands, BMKG has recorded 329 observation points, or about 7 per cent of monitoring areas, experiencing very long periods without rain, ranging from 31 to 60 days,” the agency stated.
Furthermore, maximum temperatures during the 1–5 July 2026 period still exceeded 35 degrees Celsius in several regions, including North Sumatra, Lampung, West Kalimantan, East Kalimantan, Central Java, Banten, and Central Sulawesi.
Despite this, BMKG emphasised that the dry season does not mean rain stops entirely. In early July 2026, significant rainfall was still recorded in several areas, such as West Sumatra with 156 millimetres per day, North Sulawesi with 151 mm per day, North Sumatra with 90 mm per day, North Kalimantan with 84 mm per day, and North Maluku with 57 mm per day.
According to BMKG, this rainfall is influenced by active atmospheric dynamics, including the Madden-Julian Oscillation (MJO), Kelvin waves, and Equatorial Rossby waves. Unstable local atmospheric conditions also continue to support the formation of rain clouds.
BMKG predicts that most of Indonesia will be dominated by low-category rainfall during the first ten-day period of July 2026. Around 72.19 per cent of the region is forecast to experience low rainfall, while 27.8 per cent will see medium-category rainfall, particularly in parts of northern and central Sumatra, northern Kalimantan, parts of Maluku, and the mountainous regions of Papua.
For the period of 7–10 July 2026, BMKG has warned of potential moderate rainfall in Aceh, North Sumatra, Riau, the Riau Islands, Jambi, South Sumatra, the Bangka Belitung Islands, Lampung, Banten, Central Kalimantan, East Kalimantan, North Kalimantan, North Sulawesi, South Sulawesi, Central Papua, and Papua.
Additionally, heavy to very heavy rainfall with an alert status may occur in West Sumatra, Bengkulu, Papua Pegunungan, and South Papua. Meanwhile, strong winds are forecast to affect Aceh, Banten, West Java, East Java, Maluku, North Maluku, East Nusa Tenggara, Southeast Sulawesi, and North Sulawesi.
BMKG urged residents in areas already experiencing the dry season to maintain their health by staying hydrated and reducing direct exposure to sunlight during outdoor activities.
“On the other hand, the public is also asked to remain alert to the potential for heavy rain, strong winds, and lightning that can still occur locally, and to continue monitoring weather information and early warnings from BMKG,” the agency concluded.