Songkran in Chiang Mai is the world's biggest water fight. Official dates: April 13-15, 2026. Three days of citywide water battles, ancient temple ceremonies, and cultural celebrations. This guide covers the day-by-day schedule, 6 water fight zones (Old City Moat, Tha Phae Gate, Nimmanhaemin, Night Bazaar, temples, Doi Suthep), safety tips, what to bring, budget breakdown (600-3000 THB/day), etiquette dos and don'ts, scam warnings, and transportation guide. Chiang Mai's Songkran is the wildest in Thailand - the compact Old City with its moat creates the ultimate water battle arena.