Yi Peng is a Northern Thai (Lanna) lantern festival held in Chiang Mai, coinciding with Loy Krathong nationwide — in 2026 the main dates fall on 24–25 November.
It is distinct from Loy Krathong: Yi Peng specifically involves releasing khom loi, paper sky lanterns, rather than floating baskets on water — though many people do both during the same days in Chiang Mai.
The large ticketed mass-lantern-release events (the ones you see in viral photos, with thousands of lanterns released at once) are organized privately, sell out well in advance, and change venue/organizer from year to year — always check that year's official Chiang Mai tourism announcements before buying tickets, and be cautious of resale sites.
Outside the ticketed events, many temples and neighborhoods release lanterns more informally during the festival period. Sky lantern releases are periodically restricted near Chiang Mai International Airport for flight safety, so follow local signage.