The festival is held on the night of the 12th full moon of the year in most of the countries where it is celebrated except in Laos where it coincides with the 11th full moon at the end of the rains retreat, the Buddhist Lent. In many of the Thai provinces facing Laos across the Mekong River there may also be a major festival of floating lights at that time, such as Nakhon Phanom's spectacular Lai Rua Fai (many illuminated boats). Loy Krathong may have originally been timed to coincide with the end of the life-giving rains, as a kind of harvest festival giving thanks for the abundance of the crop now filling the granaries and wishing for further bounty in the year to come. There is also a great deal of symbolism involved the floating away of the krathong representing a cleansing of sins. The symbolism may be lost where Loy Krathong is celebrated by the sea or by a large body of still water on a windy night, for the wind and the waves may return your krathong to you.

Loy Krathong has an unequalled charm and mystique whether it is celebrated on a grand scale in a major city or quietly in a small village of just a few rude huts, but for a truly breathtaking experience, the north of Thailand is the place to go. Even from the end of Lent, the build up starts with firecrackers banging and booming in the night and gradually there appear what seem to be moving orange stars in the sky. As Loy Krathong itself nears, coconut frond archways spring up at the gates of houses, earthen lamps glow in the night and paper streamers and lanterns appear everywhere.

With the rainy season gone, the night sky is clear and coolness fills the air. On the night of Loy Krathong itself the full moon sails over the horizon into a sky filled with light and sound for the Lanna folk celebrate Loy Krathong in 3 dimensions. Giant hot air balloons, called Kome Loy, rise into the sky, their fires visible, like some galaxy of orange stars, into the far distance, traditional rockets known as Bok Fai outdo the myriad other fireworks crackling and popping everywhere in the crisp night air. And beneath this frenzy of noise and light the gentle, quiet and touching act of floating (loy) one's krathong.

The traditional months of Lanna are different from the rest of Thailand, and Loy Krathong is always celebrated in Duan Yee - the second month - and the period of the festival is called Yee Peng. It is an important time with Loy Krathong and a different Buddhist ceremony called Tang Tham Luang falling within this month. The decorations around houses and temples come alive during Yee Peng with the Kome paper lanterns glowing with a host of bright colours. Walls surrounding compounds are decorated with the earthen lamps called Phang Patit. The number of these lamps must correspond with the total age of all family members combined, and their flickering yellow flames give warmth to the cool evening.

The Krathong are traditionally made from cut sections of bamboo, with neatly folded pieces of banana leaf around the edge giving the appearance of a lotus leaf. Each must be decorated with a candle, an incense stick and some flowers, though many are more elaborate. Often some grains of sand and good luck charms are placed on the Krathong, and a few coins are often added; though these usually end up as some young boy's extra pocket money. At home in the water, they swim from Krathong to Krathong and a little brown hand gropes around for what it may contain. These days the convenience and buoyancy of styrofoam have largely and unfortunately replaced traditional materials, and they litter bank and shoreline for weeks after the event.

There is a tradition that the first Krathong was made by young lady of great beauty and talent called Naang Noppamart at the royal court in Sukhothai 700 years ago, while the origins of the festival are altogether older, but of this more elsewhere.

This year, the Loy Krathong festival is from November 10 to 12. In Chiangmai, there are raft races on the river on the first day, with boat races on the next two days. The Yee Peng opening ceremony takes place at Tha Pae Gate early on the first evening, followed by a lantern parade and contest at the Night Bazaar. Beauty contests will be held at Tha Pae Gate on the second and last evenings and parades of individual Krathongs and giant Krathongs start from there on the second and third evenings. Every night there will be fireworks and Kome Loy launching, and Lanna cultural performances at the Municipal Offices near the river and of course there is nowhere better to Loy your own Krathong.