Thailand Braces for Heavy Rain Across Four Regions
Thailand's meteorological agency warns of heavy rainfall across four regions through July 15, driven by a low-pressure system and monsoon surge that could trigger flooding and dangerous sea conditions in the Andaman Sea.
The Thai Meteorological Department issued a weather forecast on July 14, 2025, warning of heavy rainfall in the northern, northeastern, and southern regions over the next 24 hours, with the eastern region particularly vulnerable to very heavy downpours. The conditions are driven by a low-pressure system over northern Vietnam combined with a strengthening southwest monsoon affecting the Andaman Sea, Thailand, and the Gulf of Thailand.
Authorities urge residents in affected areas to exercise caution against hazards from intense and accumulated rainfall, which could trigger sudden flooding and flash floods, especially in hillside areas near waterways and low-lying zones. In the Andaman Sea's upper region, waves are expected to reach 2–3 meters, exceeding 3 meters during thunderstorms. The lower Andaman Sea and upper Gulf of Thailand will see waves around 2 meters, rising above 2 meters during storms. Mariners are advised to navigate carefully and avoid areas with thunderstorms; small boats in the upper Andaman should remain ashore until July 15.
Regional forecasts through tomorrow at 6 p.m. include:
**Northern Region**: Thunderstorms in 60 percent of areas with isolated heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Tak, Phichit, and Phetchabun provinces. Low of 22–25°C, high of 31–34°C, southwest winds 10–20 km/h.
**Northeastern Region**: Thunderstorms in 40 percent of areas with heavy rain in Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Udon Thani, Mukdahan, Amnat Charoen, and Ubon Ratchathani. Low of 24–25°C, high of 30–35°C, southwest winds 10–20 km/h.
**Central Region**: Thunderstorms in 60 percent of areas, mainly in Nakhon Sawan, Uthai Thani, Chai Nat, Suphan Buri, Ayutthaya, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Songkhram, and Samut Sakhon. Low of 23–25°C, high of 33–35°C, southwest winds 10–25 km/h.
**Eastern Region**: Thunderstorms in 60 percent of areas with heavy rain in Nakhon Nayok and Prachuap Khiri Khan, and very heavy rain in Chanthaburi and Trat. Low of 23–27°C, high of 30–34°C, southwest winds 20–35 km/h. Seas 2 meters, exceeding 2 meters during storms.
**Southern Region (East Coast)**: Thunderstorms in 40 percent of areas with heavy rain in Phetchaburi, Prachuap Khiri Khan, Chumphon, and Surat Thani. Low of 23–26°C, high of 29–34°C. From Surat Thani northward: southwest winds 20–35 km/h, waves 1–2 meters inshore and 2 meters offshore, exceeding 2 meters during storms. From Nakhon Si Thammarat southward: southwest winds 15–35 km/h, waves 1 meter inshore and 1–2 meters offshore, exceeding 2 meters during storms.
**Southern Region (West Coast)**: Thunderstorms in 60 percent of areas with heavy rain in Ranong, Phang Nga, and Phuket. Low of 23–26°C, high of 31–34°C.