Thailand Braces for Heavy Rain, Flash Floods Through September 27
Thailand's meteorological department warns of heavy to very heavy rain and flash floods across 41 provinces through September 27, with the strongest rainfall expected in the lower northeast and eastern regions. The public is urged to avoid
On September 23, 2025, the Thai Meteorological Department issued Alert No. 4 (220/2025) regarding heavy to very heavy rainfall across Thailand from September 23–27. The northern region, lower northeastern region, central region including Bangkok and its vicinity, eastern region, and southern region will experience heavy rain in many areas, with very heavy rainfall in some locations. Rain is expected to begin first in the lower northeastern and eastern regions, with other areas affected in the following period.
The warning is due to a strong low-pressure system over central Vietnam's coast moving to cover the lower northeastern region, eastern region, central region, and Bangkok area along the monsoon trough passing over northern Thailand. Meanwhile, the southwest monsoon over the Andaman Sea, Thailand, and the Gulf of Thailand will intensify. The Meteorological Department identified 41 provinces with heavy rainfall.
The public is warned to be alert to dangers from heavy to very heavy rainfall and accumulated rainfall that may cause sudden flash floods and flash flooding, particularly in foothill areas near waterways and low-lying zones. Travel through roads prone to repeated flooding should be avoided, especially low areas where water may collect suddenly. Waves in the Andaman Sea and Gulf of Thailand will strengthen, with the upper Gulf experiencing waves 2–3 meters high and higher than 3 meters during thunderstorms. The lower Gulf and upper Andaman Sea will see waves around 2 meters, exceeding 2 meters during thunderstorms.
Boaters in the Gulf and Andaman Sea should exercise caution and avoid thunderstorm areas. Small boats in the upper Gulf should not leave shore from September 24–27. The public is advised to plan daily activities and travel carefully during this period and monitor updates from the Thai Meteorological Department via its website (tmd.go.th) or by calling 0-2399-4012-13 and 1182, available 24 hours daily.
