Cold surge from China to lower temperatures across upper Thailand, rough seas forecast in lower Gulf

The Thai Meteorological Department (TMD) said on Friday that another moderate to fairly strong high-pressure system from China has spread over upper Vietnam and upper Laos and is expected to cover upper Thailand and the South China Sea today (January 2, 2026).

As a result, temperatures in upper Thailand are forecast to drop by 1-3°C, accompanied by stronger winds. Cool to cold conditions are expected in the North and Northeast, while the Central region, the East, and Bangkok and surrounding areas should see cool mornings, except in the lower South.

The TMD advised people in affected areas to take care of their health during cooler conditions and to remain alert to fire hazards due to dry air and gusty winds.

In the South, the northeast monsoon, which is currently weak over the Gulf of Thailand, the South, and the Andaman Sea, is expected to strengthen, bringing isolated thundershowers.

Sea conditions are expected to worsen slightly:

• Lower Gulf of Thailand: waves around 2 metres, rising above 2 metres in thundershowers
• Upper Gulf of Thailand and offshore Andaman Sea: waves 1-2 metres, rising above 2 metres in thundershowers

All vessels in the Gulf of Thailand and the Andaman Sea are advised to proceed with caution and avoid sailing in areas experiencing thunderstorms.

The weather forecast for the next 24 hours is as follows:

North: Morning cool to cold with fog and 1-2 °C drop in temperature. Minimum temperature 13-19 °C. Maximum temperature 28-32 °C. Cold to very cold on mountain tops: minimum temperatures of 4-15 °C. Northeasterly winds 10-20 km/hr.

Northeast: Morning cool to cold with strong wind and 1-3 °C drop in temperature. Minimum temperature 13-18 °C. Maximum temperature 27-31 °C. Cold on mountain tops: minimum temperatures of 8-15°C. Northeasterly winds 15-35 km/hr.

Central: Morning cool with strong wind and 1-2 °C drop in temperature. Minimum temperature 16-19 °C. Maximum temperature 31-33 °C. Northeasterly winds 10-30 km/hr.

East: Morning cool with strong wind and 1-2 °C drop in temperature. Minimum temperature 17-23 °C. Maximum temperature 30-33 °C. Northeasterly winds 15-35 km/hr. Wave height about 1 metre and 1-2 metres offshore.

South (East Coast): Morning cool in upper part. Isolated thundershowers mostly in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, and Narathiwat. Minimum temperature 19-24 °C. Maximum temperature 29-33 °C. From Nakhon Si Thammarat upward: Northeasterly winds 15-35 km/hr. Wave height 1-2 metres and about 2 metres in thundershowers. From Songkhla downward: Northeasterly winds 20-35 km/hr. Wave height about 2 metres and above 2 metres in thundershowers.

South (West Coast): Isolated thundershowers mostly in Krabi and Trang. Minimum temperature 22-24 °C Maximum temperature 31-33 °C. Northeasterly winds 15-35 km/hr. Wave height about 1 metre, 1-2 metres offshore and above 2 metres in thundershowers.

Bangkok Metropolitan: Morning cool with strong wind and 1-2 °C drop in temperature. Minimum temperature 20-23 °C. Maximum temperature 31-33 °C. Northeasterly winds 10-30 km/hr.