Upper Thailand faces another cold morning as monsoon weakens in the south
A strong high-pressure system continues to grip the North and Northeast, keeping mornings cold, while rain and thunderstorms remain possible in parts of the South.
- Upper Thailand is experiencing cool to cold mornings, with the Northeast being the chilliest region where temperatures may drop to around 12°C due to a high-pressure system.
- The northeast monsoon over the Gulf of Thailand and the South is weakening, leading to easing rainfall and sea conditions, though isolated thunderstorms persist.
- Residents in upper Thailand are advised to take health precautions against the cold and be cautious of fire hazards, while those in the South should remain alert for thunderstorm-related hazards.
The Thai Meteorological Department’s forecast for Monday (December 29) warns of very cold conditions, particularly across upper Thailand, with the Northeast expected to be the chilliest.
Temperatures in some areas may drop to around 12°C, while Bangkok will feel cool in the morning.
The South will continue to see rainfall.
Next 24 hours: Southern storms ease, but caution remains
In the next 24 hours, rain in the lower South is expected to ease, though isolated thunderstorms will continue as a moderately strong northeast monsoon over the Gulf of Thailand and the South begins to weaken.
Residents in the South are advised to stay alert for thunderstorm-related hazards in some areas.
Sea conditions: Waves ease slightly, but rough patches are possible
Winds and waves in the lower Gulf of Thailand are easing, with wave heights of about 2 metres.
The upper Gulf will see waves of 1–2 metres, rising to around 2 metres in thunderstorm areas.
Mariners in the Gulf of Thailand and the Andaman Sea should travel with caution and avoid stormy areas, while communities along the eastern southern coastline should watch for waves breaking onto shore.
Cooler mornings nationwide; health and fire warnings
The North and Northeast will remain cool to cold, while the Central region (including Bangkok and surrounding provinces), the East, and the upper South will be cool in the morning.
This is due to a strong high-pressure system (cold air mass) still covering the North and Northeast, alongside upper-level northwesterly winds affecting upper Thailand and the upper South.
People in upper Thailand and the upper South are urged to take care of their health during the cold weather and remain cautious about fire hazards due to dry conditions.
Regional forecast from 6am Monday (December 29) to 6am Tuesday (December 30)
Bangkok and vicinity
- Cool in the morning.
- Low: 21–23°C
- High: 31–34°C
- Wind: Northeasterly 10–20 km/h
North Region
- Cool to cold with morning fog.
- Low: 13–19°C
- High: 28–32°C
- Higher elevations: cold to very cold, with frost in some places.
- Low (highlands): 2–12°C
- Wind: Northeasterly 10–15 km/h
Northeast Region
- Cool to cold in the morning.
- Low: 12–18°C
- High: 28–32°C
- Highlands: cold.
- Low (highlands): 8–14°C
- Wind: Northeasterly 10–25 km/h
Central Region
- Cool in the morning.
- Low: 16–22°C
- High: 31–33°C
- Wind: Northeasterly 10–20 km/h
East Region
- Cool in the morning.
- Low: 18–23°C
- High: 31–34°C
- Wind: Northeasterly 15–35 km/h
- Sea: Waves about 1 metre, 1–2 metres offshore
South Region (East Coast)
Upper South: cool in the morning. Lower South: thunderstorms in 40% of the area, mainly in Surat Thani, Nakhon Si Thammarat, Phatthalung and Songkhla.
- Low: 20–24°C
- High: 29–32°C
From Surat Thani northwards:
- Wind: Northeasterly 15–35 km/h
- Sea: 1–2 metres, over 2 metres in thunderstorms
From Nakhon Si Thammarat southwards:
- Wind: Northeasterly 20–35 km/h
- Sea: Around 2 metres, over 2 metres in thunderstorms
South Region (West Coast)
Thunderstorms in 20% of the area, mainly in Phang Nga, Krabi, Trang and Satun.
- Low: 23–25°C
- High: 31–33°C
- Wind: Northeasterly 15–30 km/h
- Sea: Around 1 metre; higher than 1 metre offshore and in thunderstorms
