The Lanna people of northern Thailand use "floating lanterns" ( khom loi) year round, for celebrations and other special occasions. One very important festival in which sky lanterns are used is the Lanna Yi Peng festival, which is held on a full moon of the 2nd month (ยี่เป็ง, Yi Peng) of the Lanna calendar (which coincides with Loi Krathong, the traditional festival on the 12th month of the Thai lunar calendar). During the Yi Peng festival, a multitude of lanterns are launched into the air where they resemble large flocks of giant fluorescent jellyfish gracefully floating by through the sky. The most elaborate Yi Peng celebrations can be seen in Chiang Mai,the ancient capital of the former Lanna kingdom. The festival is meant as a time to obtain Buddhist merit . In recent times, floating lanterns have become so popular with all Thai people that they have become integrated into the festival in the rest of country.
In addition, people will also decorate their houses, gardens and temples with intricately shaped paper lanterns (โคมไฟ, khom fai) of various forms. It is considered good luck to release a sky lantern, and many Thais believe they are symbolic of problems and worries floating away.
The lanterns classified into four types. “Khom Tew” is a small lantern that people use in religious ritual. It is made of a candle and colored paper. After the ceremony, it is for decoration at the temple. The second type is “Khom Kwan”, a hanging lantern. This lantern has many shapes . star shape, basket shape. The purpose of Khom Kwan is to worship a statue of the Buddha and wishing for the prosperity. People will hang it on the shelf of Buddha’s statue or hang it at the temple. The third is “Khom Pat”. Khom Pat is made of mulberry paper. The shape of the lantern is similar to a cone with two layers. There is no external pattern, but inside there is the pattern that related to Buddhism. When the lantern is lit, the light will create a beautiful shadow on the cone’s surface. The last type is “Khom loi”, a floating lantern. There are various shapes of this lantern. The main structure is made of bamboo branch, cover by kite-making paper or mulberry paper. The lantern is launched by the heat of fire same as the balloon. Normally, the places to launch the lantern are the house or the temple. Nowadays, there are many places that are organized for the festival.