Malaysia launched a three-day cloud seeding operation in Sarawak on September 3 to counter hazardous haze caused by forest and land fires in Kalimantan, Indonesia, which had worsened air quality and triggered respiratory complaints among residents. ^[1] Malaysia's environment department reported on 2026-09-04 that the Air Pollutant Index in Serian, a town in Sarawak state on Borneo Island, surged to 521, breaching the country's emergency-level threshold. ^[2] Douglas Uggah Embas, chairman of the Sarawak Disaster Management Committee, said on September 3 that the operation is essential to increase water levels before October, which he expects to be hotter and drier, and that they want to raise reservoir levels as much as possible while weather still allows. ^[3] On September 3, seven locations in Sarawak recorded Air Pollutant Index (API) readings above 300, classified as hazardous; Serian, about 60 km southeast of Kuching, had the worst API of 475, and if readings exceed 500 the government may declare a local emergency. ^[4] The Sarawak Disaster Management Committee said the cloud seeding operation targets three hydroelectric dam reservoirs and 13 water catchment areas, involving the Royal Malaysian Air Force, the National Disaster Management Agency, and the Malaysian Meteorological Department. ^[5] Indonesia's Forestry Ministry said on 2026-09-04 that satellite data detected 717 hot spots nationwide likely caused by forest fires since 2026-08-01, including 103 active hot spots in the previous 24 hours. ^[6] Unnamed Malaysian officials said on 2026-09-04 that an Air Pollutant Index reading above 500 could trigger a haze emergency declaration that would halt nonessential work and outdoor activities in the affected area. ^[7]