Bangkok: The Meteorological Department has issued a warning of increased rainfall across southern Thailand, with seven provinces on high alert for heavy downpours. The affected areas include Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Ranong, and Phang Nga.
According to Thai News Agency, the department predicts that in the next 24 hours, there will be a significant uptick in rainfall in these southern regions. This phenomenon is attributed to a low-pressure system over the Gulf of Thailand and the South, coupled with the northeast monsoon affecting the Gulf of Thailand, the South, and the Andaman Sea. Mariners are cautioned against navigating areas experiencing thunderstorms, as wave heights could exceed two meters under such conditions.
In contrast, upper Thailand is expected to experience cool mornings with sporadic rain in certain areas. Residents are advised to prioritize their health amid fluctuating weather, while farmers are encouraged to safeguard their crops from potential damage. This weather pattern is a result of the diminishing high-pressure area or cold air mass over upper Thailand and the South China Sea, alongside prevailing southeasterly winds in upper Thailand and the upper Gulf of Thailand.
The recent rainfall has led to low to moderate levels of particulate matter and haze accumulation in upper Thailand. Meanwhile, the regional weather forecast for December 12, 2025, suggests varying conditions across different parts of the country. Bangkok and its vicinity will see cool mornings with a 20% chance of rain, while northern Thailand will have a 10% chance of rain in select provinces. Northeastern and central Thailand will similarly experience cool mornings with minor chances of rain, and the eastern region may face thunderstorms in some areas.
For southern Thailand, the east coast will see 70% of its area affected by thunderstorms, with heavy to very heavy rainfall, especially in provinces like Prachuap Khiri Khan and Surat Thani. The west coast will also experience thunderstorms across 70% of the area, with heavy rain anticipated in places such as Ranong and Phuket. As a precaution, the public and local authorities are urged to stay informed and prepared for the impending weather conditions.