Vang Vieng sits in the Mekong River valley in central Laos, where the wet season from May through October brings the bulk of the year’s rainfall and the Mekong’s seasonal rise is the region’s primary flood driver.
A popular tourist town on the Nam Song River in Vientiane province, the town’s karst limestone surroundings can send heavy monsoon rain into the river quickly. Because Laos sits far upstream in the Mekong basin, a wet monsoon season here can also signal what’s coming for countries further downstream, and Laos’s Department of Meteorology and Hydrology uses radar alongside river gauges to track both direct rainfall and the river’s slower seasonal rise. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map