As an agrarian country where the majority of people are connected in some way with agriculture, Thailand needs high levels of water for farming purposes. Since most Thai farmers have to wait for seasonal rain to grow crops, they are at times faced with difficulties from drought, so there might not be enough rainfall for crop growing. During his travels to every corner of the kingdom to visit his subjects and learn about their problems, His Majesty King Bhumibol Adulyadej found that drought had become more severe in certain areas of the country and rainfall was inconsistent.

Early in his reign, His Majesty the King became interested in artificial rainmaking to assist farmers, who are very dependent on rainwater for their cultivation. At this point, he began to study artificial rainmaking techniques to seek ways of bringing down more rain to ease the drought situation. He read research work on meteorology and weather modification, which he found useful for combating weather change. In 1955, when His Majesty visited northeastern provinces, he traveled from Nakhon Phanom to Kalasin, passing through Sakon Nakhon and the Phuphan mountain range. During the trip, he looked at the sky and saw a large number of clouds moving over the vast, arid area of the Northeast. The initial conception arose from his observation that there was no rain despite heavy cloudiness. He wondered how to make the clouds move down and turn into rain. This idea was the starting point for his efforts to conduct rainmaking operations, which proved successful in the following years.

On November 14 the same year, His Majesty donated his private funds to launch the Royal Rainmaking Project, and he devoted a great deal of time and energy to develop rainmaking technology. Later, he entrusted M.R. Debariddhi Devakula, an expert in agricultural engineering at the Ministry of Agriculture and Cooperatives, to undertake research into rainmaking. M.R. Debariddhi conducted intensive research and experimentation over several years from various models applied by various countries, such as the United States, Australia, and Israel. After initial research, the first practical experiment took place over a mountain barrier at Khao Yai National Park in Nakhon Ratchasima Province in July 1969, supervised by His Majesty. The operation used light aircraft and seeded clouds with dry ice, or solid carbon dioxide. His Majesty had personally devised chemical formulae for seeding clouds in the rainmaking process. The first attempt at artificial rainmaking was successful; the clouds turned grey and rain did fall. However, there was no way to ensure that rain fell on a specific area. Then further experiments were carried out in Hua Hin District, Prachuap Khiri Khan Province, with rainfall in target areas.

His Majesty gives constant advice on target, coverage, and area, with analysis of geographical features, area selection, and other factors, to improve the accuracy and efficiency of the operations. He explained the three steps of the rainmaking process in a simplified and figurative manner:

Agitation, using weather modification techniques to form rain clouds
Fattening, or impregnating the rain clouds through the sprinkling of chemicals to make the water droplets condense
Attacking, flying the plane into the impregnated clouds, to further modify the surroundings and speed up the process.

In his royal address given at Chitralada Villa on 30 July 1986, His Majesty said:

Rainmaking is like a warship: you fire the missile far, then closer in order to properly hit the target. Since we have facilities for rainmaking, we should be sure to use it properly to get rain in the right places.

In 1971, the Government established the Artificial Rainmaking Research and Development Project within the Ministry of Agriculture and Cooperatives, which was ready to offer rainmaking services to farmers. In that year, a very dry period, one of the first places royal rainmaking activities helped was Chanthaburi, a province abundant in fruit. After it proved successful, a group of Chanthaburi residents came to Bangkok to present fruit to His Majesty to show the happy result of the rainmaking. Later in the same year, royal rainmaking activities were carried out in the central plains and the southern region to provide more extensive and effective assistance to farmers. The royal rainmaking staff reported their operations to His Majesty by radio, and His Majesty frequently offered technical suggestions in return. When their operations failed, he usually gave guidelines to solve the problem.

His Majesty pays great attention to rainmaking operations, and he sometimes gets involved with them himself, as seen from his demonstration of the rainmaking process for the Singaporean delegation at Kaeng Krachan Dam in Phetchaburi Province in 1972. Thanks to his experience, rain came within five hours, creating a great deal of excitement and certainly impressing the Singaporeans. His Majesty continually has up-to-date information from various sources, including the Internet, aerial photographs, and satellite images.

As demand for the rainmaking project has increased over the years, in 1975 the Artificial Rainmaking Research and Development Project was upgraded to be the Office of Rainmaking Operations under the supervision of the Office of the Permanent Secretary for Agriculture and Cooperatives. Later, the workload increased, and to provide greater flexibility, the Cabinet in 1992 approved the merging of the Office of Rainmaking Operations and the Agricultural Aviation Division into the Bureau of Royal Rainmaking and Agricultural Aviation under the Office of the Permanent Secretary for Agriculture and Cooperatives.

The royal rainmaking project was registered with the World Meteorological Organization in 1982, and since then, Thai and foreign experts have continued to exchange views and experience on techniques and technology. The project serves as a model for many Asian countries and brought in many requests from abroad asking for assistance in rainmaking. Indonesia sent a team to work with Thai staff several times. Bangladesh, China, Malaysia, the Philippines, Singapore, and Sri Lanka have also sent officials to learn from Thailand.

In 1986, a group of American experts and rainmaking officials were granted an audience with His Majesty the King at Daksin Palace in Narathiwat Province. His Majesty stressed the importance of rainmaking development as part of the country's water resource management. Impressed by His Majesty's initiative, the experts came up with the Applied Atmospheric Resources Research Program in a joint cooperative effort between the governments of Thailand and the United States from 1988 to 1999. An essential part of the program was the transfer of US technology to the royal rainmaking operations.

His Majesty the King in 1999 discovered a new technique to increase cloud density at both upper and lower levels simultaneously to increase the amount and extent of rainfall. The royal rainmaking team tried out the new technique and it proved to be a very efficient way of inducing rain. He named the new cloud-seeding technique "Super Sandwich." As a joke, he sent rainmaking staff at the Bureau of Royal Rainmaking and Agricultural Aviation a photo of two round sandwiches taken by him, saying "Here is the Super Sandwich." More new techniques are being discovered and introduced to the people involved. His Majesty's ingenuity for inventing the rainmaking technology has been widely recognized and has made Thailand the center of tropical rainmaking activities in this region. He has applied modern technology to existing resources to improve rainmaking potential. Non-toxic and environment-friendly chemicals, devised by His Majesty, are used to stimulate the air mass upwind of the target area to rise and form rain clouds.

When drought takes place in Thailand or other countries in the region, he sends a special team to ease the problems. In the year 2000, when Thailand faced water shortages because of impacts from the El Ni?o phenomenon, His Majesty came up with an innovation for dealing with the situation and gave it to the royal rainmaking team to use as guidelines for solving the drought problem in the Chao Phraya basin and the lower North of Thailand. The innovation helped ease the water shortage problem to a great extent.

He worked out a pictorial book, Royal Rainmaking Textbook, with his computer, teaching the steps of the rainmaking process, and on 21 March 1999, he presented copies of this book to rainmaking staff for use as guidelines. Both the royal rainmaking project and the Royal Rainmaking Textbook won the Gold Medal with Mention at Brussels Eureka 2001, held in Belgium from 13 to 18 November 2001. He also allowed the Ministry of Agriculture and Cooperatives to publish two documents on royal rainmaking. The two documents were published when Her Royal Highness Princess Chulabhorn, representing His Majesty the King, presided over the opening of a royal rainmaking research center in honor of His Majesty the King in Phimai District of Nakhon Ratchasima Province on 14 November 2001. One of the documents was on Father of Royal Rainmaking, and the other was on Our King and Royal Rainmaking.

The Cabinet, during its meeting on 20 August 2002, endorsed the proposal by the Ministry of Agriculture and Cooperatives for the title of Father of Royal Rainmaking to honor His Majesty the King and to designate November 14 each year "Father of Royal Rainmaking Day." His Majesty started the royal rainmaking project on 14 November 1955, so November 14 was picked as Father of Royal Rainmaking Day. The Cabinet decided to announce the recognition of His Majesty as the Father of Royal Rainmaking in the Royal Gazette and make it better known to the public. The decision also coincided with the occasion of Thailand's hosting the 17th World Congress of Soil Science from 14 to 21 August 2002, when the international community learned about many agricultural achievements of His Majesty the King, the greatest soil scientist of Thailand.

Drought spread to many provinces in 2005 and imposed adverse impacts on farmers. Fortunately, His Majesty had a special royal rainmaking center established in Hua Hin as a model for rainmaking operations. In his weekly radio address on 19 March 2005, Prime Minister Thaksin Shinawatra said that the Ministry of Agriculture and Cooperatives and the Ministry of Natural Resources and Environment have taken royal advice in their efforts to cope with the drought situation. He told all officials involved to offer full support for the operations of the royal rainmaking center.

In this connection, His Majesty gave advice on rainmaking techniques, seeking to extend cloud seeding from the dry season until the rainy season. He suggested that rainmaking operations follow the royal guidelines laid down in 1999 and the Royal Rainmaking Textbook. The cloud-seeding technique Super Sandwich should be applied to prevent adverse effects from hailstorms and damage to people's lives and property. According to the royal advice, rainmaking operations might continue from the day time into the night time as well, if necessary.

Royal rainmaking operations have greatly benefited farmers throughout the country, easing water shortages, and increasing agricultural production, and thereby improving the livelihood of the people. His Majesty has proved to deserve the title of Father of Royal Rainmaking, whose enlightened approach to teaching has brought guiding lights to help his subjects tackle their problems in practical ways, based on not only innovations and scientific expertise, but also appropriate technology and local wisdom and knowledge.