Thailand Deploys Rainmaking Aircraft To Reduce Hazardous Haze In Northern Provinces
Thai authorities have deployed rainmaking aircraft to northern provinces as part of an effort to reduce hazardous air pollution caused by high concentrations of PM2.5 particles. The operations, led by the Department of Royal Rainmaking and Agricultural Aviation, are focused primarily on Chiang Mai and surrounding areas where air quality has reached unhealthy levels. According to official reporting, cloud-seeding and weather modification missions were intensified to stimulate rainfall that could help disperse accumulated pollutants.
Aircraft operations target pollution hotspots
The department has deployed seven aircraft from its weather modification unit in Chiang Mai to conduct missions throughout the day. Director-General Rachen Silparaya said operations include cold-water spraying flights by CN and CASA aircraft over several districts where pollution levels have been particularly severe.
Target areas include Omkoi and Doi Saket districts in Chiang Mai and Li district in Lamphun. Additional cloud-seeding operations have also been carried out above Chiang Dao and Kalayaniwattana districts in Chiang Mai, as well as parts of Mae Hong Son province. Missions are conducted in both morning and afternoon sessions to encourage sustained cloud formation.
Rainfall expected to help disperse PM2.5 pollution
Authorities expect rainfall in targeted areas following the cloud-seeding operations. According to Rachen, sustained cloud development from repeated missions could increase the likelihood of precipitation, which may help reduce concentrations of fine particulate pollution.
Air quality monitoring showed that Chiang Mai recorded an Air Quality Index (AQI) of around 190 on the morning of 6 April 2026, categorised as unhealthy. While still concerning, this represented an improvement from an AQI of approximately 228 recorded a day earlier after previous rainmaking operations.
Wildfires and haze continue to affect northern communities
On 1 April 2026, authorities declared wildfire disaster zones in six districts of Chiang Mai as forest fires and seasonal haze intensified across the region. Northern Thailand regularly experiences severe air pollution during the dry season due to agricultural burning, forest fires and transboundary haze.
Alongside emergency interventions such as rainmaking flights, the government has also been expanding technological approaches to air quality monitoring and management. Recent initiatives include the deployment of sensor-based systems such as smart e-Nose technology to detect PM2.5 pollution and broader efforts where smart data and AI are used to improve pollution management.
These initiatives complement wider public safety and environmental monitoring strategies in the country, where digital innovation is strengthening public safety and readiness in response to natural and environmental risks.
Health risks associated with PM2.5 exposure
PM2.5 refers to airborne particles measuring 2.5 micrometres or smaller. Because of their size, these particles can penetrate deep into the lungs and enter the bloodstream. High exposure is associated with respiratory illnesses, cardiovascular complications and heightened health risks for children, older people and individuals with existing medical conditions.
Authorities continue to monitor air quality across northern provinces while deploying both operational responses and longer-term technological measures to mitigate pollution levels and protect public health.
