Safety
Flood Alert Issued for 18 Provinces in Thailand (August 19–21, 2026)
The Office of the National Water Resources (ONWR) has warned of potential flash floods and waterlogging across 18 provinces due to heavy monsoon activity.
According to a report from Khaosod Online, the Office of the National Water Resources (ONWR) has issued an alert for 18 provinces to prepare for potential flooding and waterlogging between August 19 and 21, 2026. This weather event is driven by a monsoon trough passing through the upper North and Northeast regions, combined with a strengthening southwest monsoon over the Andaman Sea and the Gulf of Thailand.
These conditions are expected to bring heavy rainfall to the North, Northeast, East, and West of the country. The ONWR specifically advises residents and travelers in these areas to remain vigilant regarding flash floods, forest runoff, landslides, and overflowing riverbanks. Urban areas with historically poor drainage are at particular risk of waterlogging.
The 18 provinces identified for monitoring include Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Phrae, Nan, Uttaradit, Tak, Nong Khai, Bueng Kan, Nakhon Phanom, Sakon Nakhon, Chanthaburi, Trat, and Kanchanaburi.
For those currently in or planning to visit these regions, it is important to monitor local weather updates and follow instructions from provincial authorities. While the ONWR has identified these specific areas as high-risk, the exact intensity of the rainfall and the specific locations of potential landslides remain subject to local environmental conditions. Travelers should exercise caution when navigating mountainous or low-lying areas during this period.