The festival held after the end of the monks’ three-month fast and retreat during the rainy season (Boun Khao Pansa). At dawn on the first day, donations and offerings are made at temples around the city. In the evening, candlelight processions are held at temples and hundreds of colorful floats decorated with flowers, incense and candles are set adrift down the Mekong River to pay respect to the river spirit. The candlelit rafts bob away into darkness, symbolically dismissing bad luck, disease, and bad deeds.

The following day in Vientiane, Savannakhet and Champasack Province, a popular and exciting boat racing competition is held to celebrate the Mekong River.