The Royal Rainmaking and Agricultural Aviation Department deployed seven aircraft on 6 April 2026 to conduct cloud seeding operations aimed at reducing PM2.5 pollution across Chiang Mai and neighbouring northern provinces. The flights targeted areas in Chiang Mai, Lamphun, Mae Hong Son and Chiang Rai as part of efforts to improve hazardous air quality.

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The operation followed similar missions on 5 April 2026, when aircraft carried out morning and afternoon flights that resulted in rainfall in Hot district of Chiang Mai, Li district of Lamphun, and Thoen district of Lampang. Additional reports confirmed rain in parts of Li district within Mae Ping National Park, measuring around 10–20 millimetres. Air quality in Chiang Mai improved from an AQI of 228 (purple level) at 08:00 to 162 (red level) by 17:00 after the operation.

At 08:00 on 6 April, Chiang Mai recorded an AQI of 190, still at a health-impacting red level, prompting continued action. From 10:30, multiple aircraft were deployed for cold water spraying and cloud seeding in areas including Omkoi, Li and Doi Saket. Further cloud seeding flights targeted Chiang Dao, Galyani Vadhana, Mae Sariang and parts of Mae Hong Son to help absorb and disperse particulate pollution.

Satellite and radar data at 12:00 indicated cloud formation had begun, with authorities planning continued operations to nurture cloud development. Expected rainfall areas included Omkoi, Mae Chaem and Mae Ai in Chiang Mai, as well as Khun Yuam, Pai and Mae Sariang in Mae Hong Son, and Phan district in Chiang Rai.

Additional flights were scheduled in the afternoon, including eight sorties from 14:30 focusing on cloud development across Chiang Mai and Chiang Rai. Further cold water spraying missions were planned from 15:00 in Omkoi, Li and Doi Saket to enhance conditions for rainfall.

Komchadluek reported that officials said the goal is to increase the likelihood of rain to help reduce airborne dust levels. Continued monitoring of weather conditions and air quality will guide further operations in the coming days.

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Adapted by ASEAN Now Komchadluek 7 Apr 2026

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Yeh because thats easier than going after the people still burning.
They're burning the jungle N/E of Kanchanaburi and aren't even trying to hide it, its been burning for a week

2 hours ago, Slowhand225 said:

Yeh because thats easier than going after the people still burning.
They're burning the jungle N/E of Kanchanaburi and aren't even trying to hide it, its been burning for a week

it's normal.

9 minutes ago, PJ71 said:

it's normal.

No way ! You can't be serious.

jesus

Is that rainmaking really working?

Wouldn't it be better to bomb the firespots with water like they do in Europe, Canada and the US?

Expect torrential and flooding in the north by the end of the month?

Yeah in CM it hasn’t rained for a long time I think their efforts to make rain so far I give a failing mark on that deal I’m surprised they don’t have planes that could just drop water on the fires or have the government go up they’re saying OK if you want the proper and the fire on it we’re gonna find you whether you start the fire or not you have to watch your own land put out the fire this has been the worst it’s ever been in CM the air is just terrible for Health but yet the government doesn’t do anything every year they talk about the same same every year it’s terrible rain making planes next thing you know is they’re gonna say big joke has been reinstated I always knew that Guy was a crook Thailand I wonder who’s making money off this red making deal I’ll tell you the people in CM are suffering I can’t even let my cat go outsideTIT

What could possibly go wrong?🤣🤣🤣

5 hours ago, Georgealbert said:

deployed seven aircraft on 6 April 2026

At a time when there is a national fuel shortage due to the US-Israel-Iran war. Better not to deploy and save fuel for the commercial airline industry.

5 hours ago, Georgealbert said:

increase the likelihood of rain to help reduce airborne dust levels.

To what degree of confidence? 10-20%? There has not been much publication as to the real predictable effectiveness of Thailand's rain making efforts. I think I read it was 50/50.

Effectiveness is heavily dependent on favorable atmospheric conditions, such as presence of appropriate clouds (all cloud types are not created equal), sufficient humidity/water content, and presence (will clouds move to or remain to where air pollution exists realizing air pollution may be stationary due to lack of air movement while clouds may move).

Any kind of artificial rainmaking is a temporary measure rather than a permanent solution to environmental issues. 

Don't think smoke clouds produce any rain

4 hours ago, Slowhand225 said:

No way ! You can't be serious.

jesus

yes. every year same time like clockwork.

BBC weather forecasts rain in CNX 15:00 today so that must be the time the flight takes off

1 hour ago, Dljohnt said:

Don't think smoke clouds produce any rain

Works in Australia when Uncle does his "Welcome to Country" smoking trick at the cricket.

First session immediately washed out.

(Uncle still collects his $10,000.)🙃🙃

It’s worth remembering that Thailand’s rainmaking operations aren’t just an ad‑hoc response to the current haze problem, they’re built on decades of scientific work pioneered by the late King Bhumibol Adulyadej.

Many people outside Thailand don’t realise that His Majesty wasn’t only a constitutional monarch but also an inventor and researcher. His work on artificial rainmaking, known as the Royal Rainmaking Project, led to several internationally recognised patents.

The most notable was the “Super Sandwich” technique, which involves a staged approach to cloud seeding using different chemicals at different altitudes to maximise condensation and rainfall. This method was innovative enough that it was patented in multiple countries, including the United States.

The King personally spent years studying meteorology, atmospheric science, and cloud behaviour, often flying in small aircraft to observe conditions firsthand. The result was a uniquely Thai approach to cloud seeding that has been used for drought relief, agriculture, and now, as we’re seeing in Chiang Mai, pollution mitigation.

Whether rainmaking is the perfect solution to the PM2.5 crisis is still debated, but the fact remains: Thailand’s capability in this area exists largely because of the late King’s scientific curiosity and long-term commitment to practical environmental solutions.

Without that foundation, deploying rainmaking planes today wouldn’t even be an option.

1 hour ago, PJ71 said:

yes. every year same time like clockwork.

No kidding captain obvious. 😂

Try arresting the arsonists setting fire to the forests.

2 hours ago, Dljohnt said:

Don't think smoke clouds produce any rain

Smoke is actually a particulate. But with that said - doesn't seem to be working. Helps of have humidity. Just saying...

6 hours ago, hanbla said:

Is that rainmaking really working?

Wouldn't it be better to bomb the firespots with water like they do in Europe, Canada and the US?

yes that would be logical, but remember where you are. there is some big money in back of this so unlikely

Heavy rain in parts of Chiang mai last night. Not enough to clear the smoke.

how about addressing the cause/s instead of this sticking plaster after the fact action?

8 hours ago, Jim Waldron said:

It’s worth remembering that Thailand’s rainmaking operations aren’t just an ad‑hoc response to the current haze problem, they’re built on decades of scientific work pioneered by the late King Bhumibol Adulyadej.

Many people outside Thailand don’t realise that His Majesty wasn’t only a constitutional monarch but also an inventor and researcher. His work on artificial rainmaking, known as the Royal Rainmaking Project, led to several internationally recognised patents.

The most notable was the “Super Sandwich” technique, which involves a staged approach to cloud seeding using different chemicals at different altitudes to maximise condensation and rainfall. This method was innovative enough that it was patented in multiple countries, including the United States.

The King personally spent years studying meteorology, atmospheric science, and cloud behaviour, often flying in small aircraft to observe conditions firsthand. The result was a uniquely Thai approach to cloud seeding that has been used for drought relief, agriculture, and now, as we’re seeing in Chiang Mai, pollution mitigation.

Whether rainmaking is the perfect solution to the PM2.5 crisis is still debated, but the fact remains: Thailand’s capability in this area exists largely because of the late King’s scientific curiosity and long-term commitment to practical environmental solutions.

Without that foundation, deploying rainmaking planes today wouldn’t even be an option.

Thank you. That was very informative. I did not know the history of the research that went into this invention or of the part played by the former king of Thailand. I do think that much more needs to be done to stop the problems that produce the PM2.5, but this does make me rethink some of my assumptions about Thailand's use of this technology.

Cloud seeding doesnt help much. The real issue is never addressed and half measures will always be front and center.

This video helps explain it.

A little info on rain and pm2.5

Should we go knock on some doors and deal with the issue directly?

Nar, lets fly some planes around and piss in the wind instead

15 hours ago, hanbla said:

Is that rainmaking really working?

Wouldn't it be better to bomb the firespots with water like they do in Europe, Canada and the US?

No, that would upset the land owners.