Intense rainfall and thunderstorms to impact 36 provinces, causing significant impact on Bangkok
Thailand is bracing for widespread heavy rain and thunderstorms on August 16, 2025, as a result of a monsoon trough, a strengthening southwest monsoon, and a low-pressure system.
Weather Conditions in Various Regions
Northern and Northeastern Provinces
The northern and northeastern provinces, including Phitsanulok, Phetchabun, Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Nan, Phrae, Tak, and others, can expect wide thunderstorms with 80% rain coverage. Heavy to very heavy rain is expected in some areas.
Eastern Provinces
Eastern provinces such as Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chon Buri, Chanthaburi, Trat will have fairly widespread thundershowers and isolated heavy rains. Temperatures will range between 24-35 °C, with southwesterly winds 15-35 km/h.
Southern Thailand - East Coast
Southern Thailand's East Coast (Chumphon, Surat Thani, Nakhon Si Thammarat) will see scattered thundershowers. Temperatures will be 23-34 °C, with moderate southwesterly winds and waves about 1 meter offshore, increasing to above 2 meters in storms.
Southern Thailand - West Coast
Southern Thailand's West Coast (Ranong, Phang Nga, Phuket, Krabi) expects fairly widespread thundershowers with isolated heavy rain. Temperatures will be 23-34 °C, southwesterly winds 15-35 km/h, and wave heights around 2 meters, rising above 2 meters in thunderstorms.
Conditions in the Andaman Sea and Gulf of Thailand
The upper Andaman Sea is experiencing waves 2–3 meters high, exceeding 3 meters in stormy areas. Small boats are advised to remain ashore until August 17 due to the hazardous conditions. The lower Andaman Sea and upper Gulf of Thailand have waves about 2 meters high, potentially rising above 2 meters during thunderstorms. Mariners are cautioned to navigate carefully or avoid sailing in stormy areas due to rough seas and strong winds.
Weather Drivers
The monsoon trough across northern and northeastern Thailand enhances rainfall. The southwest monsoon is strengthening over the Andaman Sea, Thailand, and the Gulf of Thailand, bringing moist air and unstable weather. The low-pressure system in the lower northern region contributes to enhanced convection and localized heavy rain events.
Summary
On August 16, 2025, heavy rain and thunderstorms dominate much of Thailand due to the combined effects of the southwest monsoon, the monsoon trough, and a low-pressure cell. The Andaman Sea and Gulf of Thailand experience rough sea conditions with high waves, posing risks to marine activities. Flood and flash flood warnings are in place, particularly in foothill and low-lying areas of affected provinces.
Residents are advised to be cautious of potential hazards from thunderstorms. The Thai Meteorological Department has issued a warning for widespread thunderstorms across 36 provinces. Temperatures in various regions are expected to range from 23-27°C for lows and 32-36°C for highs.
To facilitate effective weather-forecasting preparations in Thailand on August 16, 2025, residents should carefully monitor upcoming thunderstorms, as the Thai Meteorological Department has issued a warning for widespread thunderstorms across 36 provinces. The weather conditions in various regions of the country will involve widespread thunderstorms, heavy to very heavy rain, and high winds, which are largely being caused by the strengthening southwest monsoon, the monsoon trough, and a low-pressure system.
