Severe Storms Warn 29 Provinces Of Flash Flooding
Heavy monsoon rains across 29 Thai provinces through August 14 threaten flash floods in foothill areas and rough seas up to 3 meters, prompting warnings for residents and mariners nationwide.
On August 13, 2026, the Meteorological Department issued a 24-hour weather forecast predicting continued heavy rainfall in parts of the North, Upper Northeast, Central, and Eastern regions due to a monsoon trough and southwest monsoon system. Residents are warned of dangers from heavy accumulation that may trigger flash floods and flash runoff, especially in foothill and low-lying areas. Waves in the upper Andaman Sea and upper Gulf of Thailand are expected to reach 2–3 meters, exceeding 3 meters in thunderstorm zones, prompting mariners to exercise caution and small boats to avoid leaving shore.
Regional forecasts show thunderstorms in 60 percent of the North (with heavy falls in Mae Hong Son, Chiang Rai, Phayao, Nan, and Tak); 60 percent of the Upper Northeast (Bueng Kan, Sakon Nakhon, Nakhon Phanom); 40 percent of the Central region (Uthai Thani, Saraburi, Kanchanaburi); and 60 percent of the East (Nakhon Nayok, Chachoengsao, Chanthaburi, Trat) with seas reaching 2–3 meters. The South faces 40 percent thunderstorms on the east coast and 60 percent on the west coast (Phang Nga, Phuket, Krabi, Trang, Satun), with waves of 2–3 meters in the upper Andaman and 1–2 meters in the lower south, both exceeding those heights in storms. Bangkok and vicinity expect 60 percent thunderstorms with localized heavy rain, minimum 25–27°C, maximum 33–35°C, southwest winds 10–25 km/h.