Thailand's Meteorology Bureau Warns 44 Provinces of Heavy Rain

On September 8, 2025, the Thai Meteorology Department forecasts increased rainfall over the upper parts of Thailand with heavy downpours expected, particularly in the North, Northeast, and upper Central regions due to a monsoon trough passing through these areas combined with moderate southwest winds affecting the Andaman Sea, Thailand, and the Gulf of Thailand. People in these areas are warned to watch for dangers from heavy and accumulated rainfall that could cause sudden flash floods and flash flooding, especially in areas along the Mekong River basin, foothill slopes near waterways, and low-lying areas. Travel through repeatedly flooded routes should be avoided, particularly in low areas prone to temporary flooding. Waves in the Andaman Sea and Gulf of Thailand are moderate, with the upper Andaman Sea reaching approximately 2 meters; areas with thunderstorms may see waves exceeding 2 meters. Fishermen are advised to navigate with caution and avoid areas with thunderstorms. From September 9-11, 2025, the lower Northeast, Central Thailand including Bangkok and its surroundings, the Eastern region, and the lower South will experience heavy to very heavy rain in many areas with some extremely heavy rainfall, beginning first in the lower Northeast with effects reaching other regions later. This is due to the monsoon trough shifting southward across the Central, Eastern, and lower Northeast regions, combined with moderate southwest winds over the Andaman Sea and Gulf of Thailand. People in these areas must watch for dangers from heavy to very heavy rain and accumulated rainfall causing sudden flash floods and flash flooding, particularly on foothill slopes near waterways and in low-lying areas; travel through repeatedly flooded routes should be avoided, especially in low areas prone to temporary flooding. The Northern region is forecast to have thunderstorms affecting 70 percent of the area with heavy rain in some places around Nan, Uttaradit, Tak, Kamphaeng Phet, Phichit, Phitsanulok, and Phetchabun provinces; temperatures ranging 23-29°C low to 32-37°C high; variable winds at 10-20 km/h. The Northeast will see thunderstorms over 70 percent of the area with heavy rain in some places in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Khon Kaen, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Chaiyaphum, Nakhon Ratchasima, Sisaket, and Ubon Ratchathani provinces; temperatures 23-25°C low to 30-35°C high; southwest winds at 10-20 km/h. The Central region will have thunderstorms affecting 60 percent of the area with heavy rain in some places in Nakhon Sawan, Lopburi, Saraburi, and Kanchanaburi provinces; temperatures 24-27°C low to 34-35°C high; southwest winds at 10-20 km/h. The Eastern region will see thunderstorms over 60 percent of the area with heavy rain in some places around Nakhon Nayok, Prachuap Khiri Khan, Sa Kaew, Chanthaburi, and Trat provinces; temperatures 24-27°C low to 31-33°C high; southwest winds at 15-35 km/h; seas with waves 1-2 meters high, exceeding 2 meters in thunderstorm areas.