ONWR puts six provinces on flood alert as heavy rain hits Thailand
Thailand’s water authorities have warned of possible flooding, flash floods, forest run-off and mudslides in six eastern and southern provinces as a strong south-west monsoon and monsoon trough bring heavy rain.
Thailand’s Office of the National Water Resources has warned that six provinces in the East and South face a heightened risk of flooding, flash floods, forest run-off and mudslides over the next 12 hours due to heavy rainfall.
Thanarot Woraratprasert, director of the National Water Administration Centre under the Office of the National Water Resources and deputy spokesperson for the ONWR, said on June 1, 2026, that a rather strong south-west monsoon was prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.
A monsoon trough is also lying across upper Thailand, bringing more rain and heavy downpours to several parts of the country.
Six provinces under close watch
Authorities have assessed the latest rainfall forecasts and weather radar data and identified six provinces requiring close monitoring for possible flooding and accumulated rainfall.
The at-risk provinces are:
- Eastern region: Rayong, Chanthaburi and Trat
- Southern region: Ranong, Phang Nga and Phuket
Heavy rain may disrupt travel
The ONWR warned that heavy accumulated rainfall could lead to waterlogging in some areas, particularly where drainage systems are unable to cope with the volume of rain.
Such conditions could directly affect road travel and daily transport for residents in affected communities.
Risk of flash floods and mudslides
Some areas, especially low-lying communities, foothill zones and locations near waterways, are also at risk of flash floods, forest run-off and mudslides.
The warning comes as the monsoon system continues to strengthen rainfall across parts of the country, increasing the need for close monitoring in vulnerable areas.
Residents urged to follow official updates
The ONWR advised people living in flood-risk areas to prepare for possible impacts and closely follow official weather updates and disaster warnings from government agencies.
Residents are urged to remain cautious, especially during periods of heavy rain, and to monitor local announcements for the latest safety guidance.
