First rains bring relief to haze-hit Sumatra and Kalimantan as rainy season nears

JAKARTA – When heavy rain finally swept across parts of Palembang on the afternoon of Oct 24, many residents of the South Sumatran capital did not run for cover. They reached for their phones.Within hours, videos of rain drumming on rooftops and washing over streets that had been shrouded in smoke for weeks were circulating on X, Threads and TikTok, as residents celebrated a break in a dry spell lasting more than three months.“Thank God, Palembang finally got its share of heavy rain. I feel like crying,” one X user wrote alongside a video of the downpour, in a post picked up by local broadcaster Garuda TV.The rain has continued since. “We had pouring rain over the weekend, and this morning it’s lighter rain. I hope it continues,” Firmansyah, 60, a parking attendant who lives in Palembang’s 1 Ulu area, told The Straits Times by phone on Oct 26.The downpour offered a hopeful sign that relief from Indonesia’s months-long fire season may be approaching, though forecasters warn that the return of rain will be uneven.The South Sumatra station of the meteorology, climatology and geophysics agency (BMKG) expects the rainy season to begin in November, though its Jakarta-based weather forecasters have said some fire-prone areas could see it arrive in October. In the meantime, scattered showers have begun falling across Sumatra and Kalimantan, with some rain induced by cloud seeding.The return of rain following cloud-seeding operations is encouraging, as the technique requires suitable clouds to be present.As recently as Oct 6, Lieutenant-General Suharyanto, then head of the National Disaster Management Agency (BNPB), said BMKG expected rain to start falling no earlier than the third week of October, and no later than the third week of November, in South Sumatra province.By Oct 24, conditions had shifted. Siswanto, head of the meteorological station at Palembang’s Sultan Mahmud Badaruddin II airport, said the atmosphere that day favoured cloud formation, as BMKG models had predicted. Teams therefore stepped up cloud seeding using salt.In Central Kalimantan province, forecasters had flagged a high chance of rain on Oct 15 and 16 at a fire-response meeting where cloud-seeding operations were discussed. Rain fell on both days.The showers brought an outpouring of relief online. “We’re like people seeing rain for the first time,” a Palangka Raya resident wrote on Threads on Oct 16, in a post reported by Indonesian news site Wahana News.Another user quoted in the same report posted footage of rain falling into yellow-tinged air: “Even though it’s yellow today, it’s not as thick as yesterday.”In Kasongan, the capital of Katingan regency in Central Kalimantan, it was the first rain in more than three months, local outlet Berita Sampit reported.Rain remains patchy as fire risks persistFor the coming weeks, Indonesian forecasters are advising the public to expect patchy showers rather than an abrupt change of season.BMKG’s South Sumatra station expects October rain to stay relatively light, with the rainy season setting in across the province in November. South Sumatra has endured a dry season lasting more than four months, with some areas going more than 100 days without rain.BMKG still lists South Sumatra, Jambi, Bengkulu, Lampung and Bangka Belitung as provinces at risk of fires through Oct 31.Riau province entered its rainy season in September, helping to reduce the number of hotspots, BMKG said.BMKG also said in September that the southern parts of Central and West Kalimantan would enter the rainy season in October. Its Palangka Raya station forecasts rain in the city from Oct 27 to 30. But relief cannot come soon enough: on Oct 25, visibility in parts of the city fell to about 50m as haze thickened, local media reported.South Kalimantan’s climate station expects below-normal rainfall through the end of October. In East Kalimantan, the rainy season is forecast to begin in western and central areas in late October, and in most other areas by mid-November.The ASEAN Specialised Meteorological Centre has said more showers during the inter-monsoon period towards the end of October could begin to ease the hotspot and haze situation across the region.Forest fires across Indonesia, particularly on the islands of Sumatra and Kalimantan, have been exacerbated by a strong El Nino weather phenomenon, sending haze across the region this year.