Rainfall has helped with firefighting efforts in the forests and plantations of Kalimantan and Sumatra, but new hot spots have emerged in Papua, in the eastern part of Indonesia.
The number of hot spots picked up by satellites on Monday afternoon was 158 across Indonesia, with Papua having the highest number, according to Indonesia's disaster management agency (BNPB).
"The dry season will last until October and will peak in September. The potential for drought and forest and plantation fires will increase," said BNPB's spokesman, Dr Sutopo Purwo Nugroho, in a press statement.
The most affected areas are Papua, with 93 hot spots; East Java, with 17 hot spots; and West Nusa Tenggara, with 11 hot spots. Most of the fires in Papua were in the Merauke regency.
Forest and plantation fires have plagued Sumatra and Kalimantan for decades, especially in the provinces of Riau, Jambi, South Sumatra, West Kalimantan, South Kalimantan and Central Kalimantan. Similar blazes have appeared in Papua since 2015, according to the BNPB statement.
"Fires have emerged in Merauke and Mappi regencies in Papua since 2015... mainly due to massive land clearings to make way for plantations there," Dr Sutopo said. "Based on satellite monitoring, the converting of forest land into plantation has taken place quite swiftly in Papua."
Most of the hot spots were located in hard-to-reach corners, and a lack of equipment and personnel to help with firefighting efforts has complicated the problem, Dr Sutopo explained.
He added that an estimated 354,191ha of forest and plantation land in Papua have been burnt between Jan 1, 2015, and Oct 20, 2015, an area about five times the size of Singapore.