Naga Fireball Festival

On the night of the full moon that ends Buddhist Lent, usually in October, reddish glowing balls rise from the Mekong along a stretch of the Nong Khai bank, ascend some tens or hundreds of metres and vanish. Local belief holds that they are made by the naga, the serpent of the river, marking the Buddha's return from preaching to his mother. Tens of thousands of people line the bank at Phon Phisai and elsewhere to watch. What causes them is genuinely disputed: proposed explanations include the ignition of methane and phosphine from riverbed sediment, and a widely reported television investigation in 2002 claimed tracer rounds fired by soldiers on the Lao side, which caused considerable public anger in Thailand and did not settle the question. Numbers of fireballs vary hugely year to year. Traffic and crowds along the riverbank are extreme, and accommodation books out months ahead.

What to look for

• The fireballs - reddish lights rising from the river and vanishing.
• The riverbank crowds - tens of thousands lining the Mekong at Phon Phisai.
• The naga belief - the serpent explanation the festival is built on.
• The dispute - methane, phosphine and the contested 2002 tracer claim.

When to go

October, on the full moon that ends Buddhist Lent - the date moves each year. Numbers of fireballs vary enormously and some years are disappointing.

Good to know

The cause is unresolved and the 2002 tracer claim remains contested and locally resented. Fireball numbers vary wildly year to year. Traffic and crowds are extreme and accommodation books out months ahead. Nothing is guaranteed.

Nearby

Nong Khai town and Sala Kaew Ku are west; the Mekong runs the length of the province.