Monsoon Brings Heavy Rain to 39 Provinces; Flood Alert Issued

The Disaster Prevention and Mitigation Department reported on August 16 that monsoon conditions will bring heavy to very heavy rainfall across northern Thailand between August 18-21, 2025, particularly in the North and Northeast regions due to a monsoon trough coupled with a strong southwestern monsoon over the Andaman Sea and Gulf of Thailand. The northern Andaman Sea will see rough conditions with waves 2-3 meters high, rising above 3 meters during thunderstorms. The lower Andaman Sea and northern Gulf of Thailand will experience waves around 2 meters, exceeding 2 meters in thunderstorm areas.

Seventeen northern provinces are on alert for flash floods, flash floods, mudslides, and water accumulation: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Phrae, Nan, Uttaradit, Tak, Sukhothai, Kamphaeng Phet, Phichit, Phetchabun, Nakhon Sawan, and Uthai Thani. Fifteen northeastern provinces including Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Kalasin, Mukdahan, Roi Et, Yasothon, Amnat Charoen, Surin, Si Sa Ket, and Ubon Ratchathani are also at risk. Seven central provinces—Kanchanaburi, Ratchaburi, Saraburi, Nakhon Nayok, Prachuap Khiri Khan, Chachoengsao, and Trat—face similar threats.

Three southern provinces face strong wind warnings: Ranong (Muang, Kapoe, and Suksamran districts), Phang Nga (Kuraburi, Takua Pa, Thai Mueang, Takua Thung, and Ko Yao districts), and Phuket (all districts). The department has alerted 42 provinces and regional disaster prevention centers to prepare emergency response teams, monitor rainfall and water levels, and issue closures for risky natural attractions including waterfalls and caves. Officials are directed to drain flood-prone areas and prepare temporary shelters. Maritime traffic is strictly banned in affected areas.