The sporadic but heavy rainfall since Tuesday, coupled with ramped-up cloud-seeding efforts by Indonesia to create more rain, has finally soothed the ground and cleared the air in Kalimantan and Sumatra.
Not only did air pollution levels fall substantially across the two islands yesterday, but visibility in the skies has also improved.
"With the rainfall over three consecutive days in Sumatra and Kalimantan, the hot spots have been significantly reduced," Dr Sutopo Purwo Nugroho, head of data and information at Indonesia's national disaster management agency (BNPB), said at a press briefing yesterday.
Dr Sutopo said that as of 5am, only 156 hot spots remained in Sumatra. In Kalimantan, there were just four. "A week ago, South Sumatra had 703 hot spots and Kalimantan had 905," he added. Hot spots are technical terms for fires detected in forests or on peatland, typically started by farmers or errant plantation operators to clear land for cultivation.
At the height of the crisis, thousands of such fires, which produced the toxic haze, were spotted in Kalimantan and Sumatra by satellites.
The Indonesian National Institute of Aeronautics and Space said yesterday that the fires behind the smouldering thick haze, which has covered many parts of South-east Asia in recent weeks, have ravaged 2.1 million ha of land in Indonesia.
That is the equivalent of burning the entire island of Singapore almost 30 times over. It is also higher than an earlier estimate of 1.7 million ha revealed by President Joko Widodo.
Yesterday was the second day Mr Joko was back in Indonesia, after he cut short his visit to the United States to oversee the crisis at home.
The President and First Lady Iriana travelled to affected areas in Palembang and Jambi in Sumatra to inspect evacuation centres and other relief shelters. "I saw a good relief shelter where there are medical personnel, medical supplies, so it's complete," he said.
Visibility in Pekanbaru, Riau, reached 3,000m yesterday, while it was 1,400m in Jambi in Central Sumatra. Palangkaraya in Central Kalimantan had visibility of 1,200m despite hazy conditions, while it was as far as 2,500m in Banjarmasin in the south, said Dr Sutopo.
The Sultan Thaha Airport in Jambi reopened yesterday after being closed for the last two months.
The improved visibility is a welcome development for local aviation players, after they suffered thousands of flight cancellations and delays due to the haze.
In the meantime, the Pollutant Standards Index (PSI) readings continued to fall across Kalimantan and Sumatra. In Palembang in South Sumatra, the PSI hovered under 200 in the morning before peaking at 258 at noon yesterday. The index peaked at 430 on Thursday.
The PSI reading for Pekanbaru never rose above 77 and was as low as 38 at noon. In Jambi, the PSI peaked at 154, then fell to 20 at noon.
Palangkaraya, for most of yesterday, remained under the 116 level, in the moderate range of the PSI. It was a vast improvement from the four-digit readings that for weeks were the norm for the city.
BNPB has said that if the favourable weather persists, it expects to put out all hot spots by the end of next month or early December. "In the next four days, there will still be an abundant amount of rainfall, according to our forecast," said Dr Sutopo. "So this is our golden opportunity (for more cloud-seeding) because after this four-day window, there is a chance we are going back to drier conditions again."
Indonesian air force chief Agus Supriatna told Kompas news that the government plans to acquire four Beriev Be-200 water bombers. The Russian-made aircraft was found to be more effective in firefighting operations.
Meanwhile, people out and about yesterday at Pasar 26, a traditional market in Palembang, were relieved as conditions improved.
"The market is always open and sees crowds regardless of how bad the haze is," said 51-year-old Saiful, a fish-cracker hawker. "Only now people have more relaxed faces."