Indonesia is carrying out cloud-seeding operations to induce rain in regions prone to forest fires. This will continue until the dry season ends in September.
A bad spell of forest fires, like those that occurred last year, could spread haze throughout the region, including Singapore.
The dry season started last month and will peak in August and September in different parts of the sprawling archipelago.
Since the middle of this month, cloud-seeding operations have been carried out over wet peatlands in a few areas in Riau province, including Rokan Hulu, Rokan Hilir, Dumai, Bengkalis and Pelalawan, said Mr Tri Handoko Seto, head of the weather modification technology division of the Agency for the Assessment and Application of Technology (BPPT).
"Since early May, the level of the water table in the peatland has dropped. Therefore, we have to wet it again," he told The Straits Times.
"By wetting the fire-prone peatlands, we have reduced the chance of potential fires in the areas. Right now, there are no hot spots in Riau," he added.
Riau, which is close to Singapore, is among six provinces in Sumatra and Kalimantan - the Indonesian part of Borneo - that are usually hardest hit by forest fires. The other five are Jambi, South Sumatra, West Kalimantan, Central Kalimantan and South Kalimantan. All six were ablaze during the prolonged dry season last year.
Peatlands are easily combustible, and fires that break out on them are harder to extinguish as they can burn underground for weeks, producing thick haze.
The BPPT plans to continue its cloud-seeding operations in South Sumatra next month, and in some Kalimantan provinces later, until the end of the dry season, Mr Tri said.
The Meteorology, Climatology and Geophysical Agency (BMKG) in late March forecast a "wetter" dry season for most of Indonesia this year than last year.
About 30 per cent of the country, however, is likely to experience a drier-than-usual season. These areas include the northern parts of Sumatra as well as parts of Java, Bali, Nusa Tenggara and East Kalimantan. The southern parts of Sulawesi as well as the west and south of Maluku are also likely to be dry.
BMKG's head of climate variability analysis Indra Gustari said that while the dry season began in April in regions such as Jakarta and Banten in Java, and Bali, it would only start at the end of May or early to mid-June in various areas in Riau.
"The dry season will peak in June in most parts of Riau, except its central regions where it will peak in July," he said, noting the short period between the start and the peak of the dry season in the province.
Mr Indra also said the next monsoon season was expected to begin in October to December in different parts of the country.
The agency will release its monsoon season forecast in August.
President Joko Widodo early this month warned the Cabinet about "a dry season that is drier than usual", which would affect agriculture. He ordered that necessary measures be taken to mitigate its impact, such as by ensuring water availability in key farming areas.
If left unaddressed, a drought could threaten Indonesia's food security as it battles the Covid-19 epidemic, which has already killed 1,473 people and infected 23,851 in the country.
The United Nations Food and Agricultural Organisation has already warned about a potential global food crisis amid the ongoing pandemic.