On Java, firefighters battled a blaze for a ninth day at Bromo Tengger Semeru National Park, where nearly 900 hectares have burned since the fire began last week. The popular tourist site has been closed to visitors since Saturday.
The fire is among several blazes that have drawn nearly 50,000 firefighters nationwide.
Indonesia is forecast to face an unusually severe dry season this year, with elevated risks of drought and wildfires partly due to El Niño, the BMKG weather agency said.
More than 107,000 hectares have burned nationwide this year, twice the area lost to fires in 2023.
At Bromo, about 200 firefighters, forest rangers, police and soldiers were supported by three water-bombing helicopters and fire trucks.
“We’re making our best effort and mobilizing everything... to extinguish and wet-down the area,” local disaster official Satriyo Nurseno told Agence France-Presse (AFP).
“We hope that today we can put out the fire in all areas, then carry out soaking so that the fire does not reignite.”
More than 48,000 personnel have been deployed to fight fires in six provinces, while 43 helicopters and up to 15 fixed-wing aircraft have been mobilized for cloud seeding.
The BMKG said average temperatures in July reached 27C, the highest July average since 1991.
El Niño typically brings drier conditions to India and Southeast Asia.