Songkran Thai New Year (April 13–15 Nationwide)
UNESCO-listed Songkran marks the traditional Thai solar New Year at the height of April's hot season. Expect joyful street-wide water splashing along Bangkok's Silom Road, Khao San Road, and Siam Square, and a 5-day celebration around the Chiang Mai Old City Moat. Always carry your phone and cash inside a sealed waterproof neck pouch, and never splash monks, elderly people, or motorcyclists.
Loy Krathong & Chiang Mai Yi Peng Lanterns (Full Moon of the 12th Lunar Month — November)
On the November full moon evening, millions of Thais float banana-leaf lotus baskets (krathongs) on rivers to thank the Water Goddess Phra Mae Khongkha, while Northern Thailand celebrates Yi Peng with illuminated Lanna paper lanterns around Chiang Mai's Tha Phae Gate and Nawarat Bridge.