Loy Krathong (or Loi Kratong, Thai ลอยกระทง) is a festival celebrated annually throughout Thailand. It takes place on the night of the full moon of the twelfth month of the traditional Thai lunar calendar; in the Western calendar it usually comes to coincide with that of November.
"Loi" means "to float". "Krathong" is a raft about a span in diameter traditionally made from a section of banana tree trunk (although modern versions often use styrofoam, an insulating plastic material), decorated with leaves from the same plant, flowers, lanterns, incense sticks, etc.
During the night of the full moon, many people make small rafts like these and sail them down the river. Government departments, large companies and other organizations build much larger and more elaborate rafts, which take part in competitions. In addition, during the festival, fireworks shows and beauty contests take place.
The festival probably had its origin in India; it would be, therefore, a Hindu festival similar to Diwali, in which floating lanterns are deposited on the Ganges as an expression of gratitude to the deity of the river for the life granted throughout the year.
According to the writings of H.M. King Rama IV (1863), the festival, Brahmanical in its origin, would have been adapted by Thai Buddhists as a ceremony in honor of Lord Buddha.
In addition to venerating the Buddha with the lights of the candles of the small rafts, the act of sailing them on the river would symbolize the renunciation and overcoming of all grudges, bad moods and weaknesses of each one, in order to start a new life without them.
In the old days, Thais used to have their fingernails and hair cut and floated with the rafts as a symbol of the negative parts of oneself being left behind. Many Thais believe that floating a "krathong" will bring them good luck and do so in honor and gratitude to the water goddess, Phra Mae Khongkha.
The beauty pageants that accompany the Festival are known as "Noppamas Queen Pageants". According to legend, Noppamas was the consort of King Loethai of Sukhothai (14th century) and the first to float decorated "krathongs".
The Thai tradition of Loy Kratong originated in the province of Sukhothai, although it is now celebrated throughout the country, with the festivals organized in Chiang Mai and Ayutthaya being particularly well known for their colorfulness.