Bangkok: The Meteorological Department reports increased rainfall in Thailand and warns of very heavy rain in the upper Northeastern and Eastern regions, particularly Bueng Kan, Sakon Nakhon, Nakhon Phanom, and Mukdahan provinces. Beware of flash floods and mudslides. Waves in the upper Andaman Sea and the upper Gulf of Thailand are expected to strengthen.
According to Thai News Agency, the Meteorological Department forecasts that over the next 24 hours, Thailand will experience increased rainfall, with some heavy rain in the northern and southern regions, and very heavy rainfall expected in the upper northeastern and eastern regions. Residents in Bueng Kan, Sakon Nakhon, Nakhon Phanom, and Mukdahan provinces are advised to be cautious of the dangers of heavy to very heavy rainfall and accumulated rainfall, which could lead to flash floods and forest runoff, particularly in hillsides near waterways and lowlands. This situation arises from the monsoon trough passing over the upper northern and northeastern regions, combined with the moderate southwest monsoon prevailing over the Andaman Sea, Thailand, and the Gulf of Thailand, which is strengthening.
The southwest monsoon prevailing over the Andaman Sea, Thailand, and the Gulf of Thailand will intensify. Waves in the upper Andaman Sea and the upper Gulf of Thailand will intensify, with waves reaching 2-3 meters high. Waves will exceed 3 meters in areas with thunderstorms. Mariners are advised to proceed with caution and avoid sailing in areas with thunderstorms. Small boats in the upper Andaman Sea and the upper Gulf of Thailand should remain ashore. Residents along the eastern coast and the upper western coast of the southern region should beware of the dangers of waves hitting the shore from August 30 to September 2, 2025.
Furthermore, a depression over the central South China Sea is expected to intensify into a tropical storm and is expected to make landfall near Quang Binh, Vietnam, this evening (August 30, 2025). It will then weaken into a depression, moving over northern Laos and further weakening into a strong low-pressure area moving along the monsoon trough, covering northeastern Thailand tonight (August 30, 2025) and then covering the northern region tomorrow (August 31, 2025).
The weather forecast for Thailand from 6:00 AM today to 6:00 AM tomorrow indicates thunderstorms in various regions. The northern region will have 60% coverage with heavy rain in some areas of Nan, Phrae, Uttaradit, and Phetchabun provinces. The northeastern region will experience thunderstorms covering 70 percent of the area, with strong winds and heavy to very heavy rain in several provinces. The central region will experience thunderstorms in 40% of the area, mostly in Kanchanaburi, Ratchaburi, Lopburi, and Saraburi. The eastern and southern regions will also see significant thunderstorm activity, with varying degrees of heavy rain and wind conditions. Bangkok and surrounding areas will experience thunderstorms in 40% of the area.