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Flash Flood Warning Hits 24 Provinces Across Thailand
Thailand's National Water Resources Office (NWR) has issued a flash flood warning covering 24 provinces in the North, Northeast, and East of the country. The warning runs from September 4 to 8, 2026, and was first published on the NWR's Facebook page on September 4. It comes as a monsoon trough moves across the North and upper Northeast at the same time as a moderate southwest monsoon covers the Andaman Sea, Thailand, and the Gulf of Thailand. The overlap of these two weather systems is expected to bring heavy to very heavy rain, raising the risk of flash flooding, mudslides, and landslides in the affected areas. No provinces in southern Thailand, including Krabi or Koh Lanta, are included in this warning.
Why the Warning Was Issued
The NWR says the combination of the monsoon trough and the southwest monsoon overlapping during this watch period is the direct trigger for the alert. The office is calling for vigilance in the named provinces through September 8, pointing to the risk of flooding in communities that are already prone to it, flash flooding, runoff from forest areas, mudslides and landslides, and waterlogging in low-lying spots.
Which Provinces Are Affected
24 provinces are covered by the warning, split across three regions.
<table> <tr><th>Region</th><th>Provinces</th></tr> <tr><td>North (11)</td><td>Mae Hong Son, Tak, Chiang Mai, Chiang Rai, Phrae, Phayao, Nan, Uttaradit, Phitsanulok, Sukhothai, Phetchabun</td></tr> <tr><td>Northeast (11)</td><td>Chaiyaphum, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Yasothon, Roi Et, Amnat Charoen, Ubon Ratchathani</td></tr> <tr><td>East (2)</td><td>Chanthaburi, Trat</td></tr> </table>
What It Means for Travelers
If you have plans in northern Thailand (Chiang Mai, Chiang Rai, the Pai or Mae Hong Son area, Sukhothai) or the northeast (Isan provinces near the Mekong and Lao border, including Ubon Ratchathani and Nong Khai) between September 4 and 8, 2026, expect the possibility of heavy rain, flash flooding, and disruption to road travel, including flooded roads and landslides in mountainous areas.
Travelers heading to the eastern seaboard, particularly Chanthaburi or Trat (the gateway to Koh Chang), should also keep an eye on conditions there.
Southern Thailand, including Krabi and Koh Lanta, is not named in this warning.
If you're traveling through any of the listed provinces, it's worth checking local conditions before heading out by road, especially around low-lying or flood-prone areas, and keeping an eye on updates from the NWR and the Thai Meteorological Department through September 8.
Information sourced from The Thaiger.