The northern Thai festival featuring the release of sky lanterns is Yi Peng.
Yi Peng is a traditional Lanna festival celebrated in northern Thailand, especially around Chiang Mai. Its most recognizable ritual is releasing khom loi—lightweight lanterns made from paper or fabric stretched over a frame. A candle or fuel cell heats the air inside, creating lift and sending the lantern upward.
The festival is rooted in Theravada Buddhist practice and merit-making. Participants may release lanterns as offerings, wishes, or symbols of letting go of misfortune. Yi Peng follows the Lanna lunar calendar and usually culminates around the full moon of its second month, generally in November.
Yi Peng overlaps with Loy Krathong, which explains frequent confusion between them. In Chiang Mai, both can appear together: Loy Krathong sends decorated floats onto water, while Yi Peng sends lanterns into the sky. Lantern releases are regulated because of fire and aviation hazards.