Thailand's Meteorology Department warns 42 provinces of heavy rainfall through July 25 as a strengthened southwestern monsoon and low-pressure systems bring thunderstorms to northern, northeastern, and eastern regions, with rough seas expec
The Meteorology Department's 24-hour forecast issued on July 22, 2569 indicates rainfall will increase across Thailand, with heavy downpours in parts of the northern, northeastern, and eastern regions due to a strengthening southwestern monsoon and an active low-pressure system over northern Vietnam. Residents in the northern and upper northeastern regions are warned of dangers from heavy and accumulated rainfall.
The upper Andaman Sea and upper Gulf of Thailand will experience 1–2 meter waves, while the lower Andaman Sea will see approximately 1-meter waves; thunderstorm areas may see waves exceeding 2 meters. Boaters are advised to proceed with caution and avoid thunderstorm zones.
A separate low-pressure system over the Pacific Ocean is expected to intensify into a depression and move toward the upper Philippines between July 24–25, 2569.
Regional forecasts show the Northern Region with 60 percent thunderstorms and heavy rain in Maehongson, Chiang Mai, Chiang Rai, Phayao, Phrae, Nan, Uttaradit, Lamphun, Lampang, and Tak; temperatures between 22–34°C; southwest winds 10–20 kph.
The Northeastern Region will have 60 percent thunderstorms and heavy rain mainly in Nong Khai, Udon Thani, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Mukdahan, Amnat Charoen, and Ubon Ratchathani; temperatures 23–35°C; southwest winds 10–20 kph.
The Central Region will see 40 percent thunderstorms mostly in Nakhon Sawan, Uthai Thani, Chai Nat, Lopburi, Saraburi, Kanchanaburi, and Ratchaburi; temperatures 25–36°C; southwest winds 10–20 kph.
The Eastern Region will have 60 percent thunderstorms and heavy rain in Nakhon Nayok, Prachuap Khiri Khan, Chanthaburi, and Trat; temperatures 23–35°C; southwest winds 15–35 kph; seas with 1–2 meter waves, exceeding 2 meters in thunderstorm areas.
The Southern Region (east coast) will experience 30 percent thunderstorms mainly in Phetchaburi, Prachuap Khiri Khan, Phatthalung, Songkhla, Pattani, Yala, and Narathiwat; temperatures 23–36°C; southwest winds 15–30 kph; seas approximately 1 meter, exceeding 1 meter offshore and 2 meters in thunderstorm zones.
The Southern Region (west coast) will have 40 percent thunderstorms mostly in Ranong, Phang Nga, Phuket, Krabi, and Trang; temperatures 23–35°C. From Phang Nga northward: southwest winds 15–35 kph; seas 1–2 meters, exceeding 2 meters in thunderstorms. From Phuket southward: southwest winds 15–30 kph; seas approximately 1 meter, exceeding 2 meters in thunderstorm areas.
Bangkok and surrounding areas will have thunderstorms with 60 percent coverage.