Thai Meteorological Department warns of heavy rain and temperature shifts

The Thai Meteorological Department issued weather warnings on November 14 and 15, 2026, regarding heavy rain in Southern Thailand and shifting temperatures in Upper Thailand. Southern Thailand is expected to experience continuous heavy rain from November 18 to 22, 2026, with some areas seeing very heavy rain. This weather pattern follows a period of assessment regarding two rain waves occurring between November 11 and 21, 2026.

Southern weather monitoring and rain waves

The National Water Resources Office is currently monitoring 8 provinces located on the Gulf of Thailand coast due to the potential impact of a second wave of heavy rain. This second wave is expected to occur between November 18 and 21, 2026. The 8 provinces under special monitoring by the National Water Resources Office include Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, and Narathiwat.

While some reports indicate that 13 Southern provinces are facing heavy rain, the National Water Resources Office has specifically identified these 8 provinces for special monitoring. In the 24-hour period starting November 14, 2026, the lower region of the Gulf of Thailand experienced waves approximately 2 meters high. These wave heights are expected to increase to over 3 meters in areas experiencing thunderstorms.

Temperature shifts in Upper Thailand

Upper Thailand will undergo significant weather changes between November 18 and 22, 2026. The region will initially experience thunderstorms and strong winds, followed by a drop in temperature and the arrival of cold weather. According to the November 15 forecast, temperatures in Northern and Northeastern Thailand are expected to rise by 1-2 degrees Celsius.

In the 24-hour period starting November 14, 2026, the minimum temperature in Northern Thailand was forecasted to be between 16-22 degrees Celsius. In higher elevations, mountain peaks may reach temperatures between 10-15 degrees Celsius. These temperature shifts follow reports that temperatures in Upper Thailand will rise by 2 degrees Celsius.

Meteorological agency assessments

The Thai Meteorological Department serves as the official agency for weather forecasting in Thailand, while the National Water Resources Office manages water resource monitoring. These agencies are tracking the progression of weather systems to manage the potential impacts of heavy rainfall and temperature fluctuations across different regions of the country.

Glossary

• National Water Resources Office — The Office of the National Water Resources is Thailand's command centre for management of the nation's water resources. It is responsible for water resource monitoring.
• Southern Thailand — Southern Thailand is the southernmost cultural region of Thailand. It is located on the Malay Peninsula and is separated from Central Thailand by the Kra Isthmus.
• Northern Thailand — Northern Thailand is a region that contains the Northern Thailand–Laos moist deciduous forests ecoregion. This area features river valleys running north–south between mountain ranges.
• Gulf of Thailand — The Gulf of Thailand is a shallow inlet adjacent to the southwestern South China Sea. It is bounded between the southwestern shores of Mainland Southeast Asia and the northern half of the Malay Peninsula.
• Chumphon — Chumphon is a location featuring a 222-kilometre coastline and various beaches such as Hat Thung Wua Laen and Hat Saphli. It includes the Prince of Chumphon Shrine and the fishing village of Ban Tha Samet.