The Royal Rainmaking Department is tackling haze by deploying seven aircraft for continuous flights spraying water and dispersing dry ice to clear dust, nurturing clouds, and accelerating rainfall in additional target areas.
At 14:00 on 5 April 2026, Rachen Silparaya, Director-General of the Royal Rainmaking and Agricultural Aviation Department, revealed that the department continues its rainmaking operations. Monitoring air quality in Chiang Mai province since 08:00 showed severe health-impacting conditions (purple level) with an AQI of 228. Today's weather conditions, with relative humidity conducive to rainfall, prompted orders for the Chiang Mai weather modification unit to plan flights to disperse dust extensively and induce rainfall today.
Earlier this morning, six flights were conducted: one CN aircraft sprayed cool water over Doi Saket and Hang Dong districts of Chiang Mai; CASA aircraft No. 1 dispersed dry ice at 10:30 over Doi Saket, Chiang Mai; CASA aircraft No. 2 dispersed dry ice at 11:10 over Doi Saket, Chiang Mai; L410 aircraft No. 1 conducted cloud seeding over Kalayaniwattana and Mae Chaem districts, Chiang Mai; and L410 aircraft No. 2 seeded clouds over Mae Sariang, Mae Hong Son, and Omkoi, Chiang Mai.
In the afternoon, seven rainmaking aircraft conducted eight additional flights: at 13:30, CASA No. 1 sprayed cool water over Mae Sariang, Mae Hong Son, and CASA No. 2 sprayed cool water over Hod, Chiang Mai; at 14:30, L410 No. 1 dispersed dry ice over Hang Dong, Chiang Mai, and L410 No. 2 dispersed dry ice over Mueang Pan, Lampang; at 15:00, CN aircraft sprayed cool water over Doi Saket, Chiang Mai to reduce dust in Chiang Mai, Chiang Rai, Lampang, and Mae Hong Son provinces.
At 15:00, cloud nurturing operations were planned to manipulate weather conditions to induce rainfall. CASA No. 1 nurtured clouds to absorb and disperse dust over Mae Taeng and Kalayaniwattana districts, Chiang Mai, continuing operations over Omkoi, Chiang Mai. CASA No. 2 nurtured clouds over Wiang Pa Pao and Mae Suai districts in Chiang Rai.
Rachen added that after today's operations, weather radar monitoring will track cloud development. It is expected that continuous rainfall will occur over targeted operational areas, contributing to ongoing reduction of haze problems in northern Thailand.
