Upper Thailand stays chilly, foggy; south rains ease
Upper Thailand remains cool to cold with fog and thick fog in places, lows at 14°C in the North and Northeast, while southern rains ease as monsoon weakens
Thailand’s upper regions will remain cool to cold over the next 24 hours, with morning fog and patches of thick fog in parts of the North and Central regions, as the northeast monsoon begins to weaken, the Meteorological Department said.
In its forecast for the period from 6pm on December 30, 2025 to 6pm on December 31, 2025, the department said upper Thailand would see light fog in the morning, while some areas in the North and Central regions could experience thick fog. 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 feel cool in the morning.
The department said upper-level northwesterly winds continue to cover upper Thailand and the upper South, while the moderate high-pressure system or cool air mass over the North and Northeast is weakening.
People in affected areas were urged to take care of their health in the continued cool conditions, remain alert to fire risks due to dry weather, and exercise extra caution when travelling through foggy areas.
South: fewer rains as monsoon weakens
The northeast monsoon over the Gulf of Thailand and the South is easing, leading to reduced rainfall in the lower South, though isolated thunderstorms are still possible.
Waves in the lower Gulf are expected to remain moderate at 1–2 metres, rising to around 2 metres in thunderstorm areas. Mariners in the Gulf of Thailand and the Andaman Sea were advised to navigate with caution and avoid stormy areas.
Dust and haze
The department said upper Thailand is seeing dust and haze accumulation at moderate to fairly high levels due to poor air ventilation.
Regional outlook (6pm today to 6pm tomorrow)
North: Cool to cold with morning fog and thick fog in some areas. Lows 14–18°C, highs 29–32°C. Mountain tops cold to very cold, with frost in some spots; lows 5–15°C.
Northeast: Cool to cold with morning fog. Lows 14–17°C, highs 30–32°C. Mountain tops cold; lows 8–12°C.
Central: Cool mornings with fog; thick fog in some areas. Lows 17–20°C, highs 32–34°C.
Bangkok and vicinity: Cool mornings with fog. Lows 20–23°C, highs 32–34°C.
East: Cool mornings with fog. Lows 18–23°C, highs 31–35°C. Seas around 1 metre.
South (east coast): Upper section cool mornings with fog; lower section thunderstorms in about 10% of areas, mainly Nakhon Si Thammarat, Phatthalung and Songkhla. Seas 1–2 metres in the lower section, about 2 metres in storms.
South (west coast): Thunderstorms in about 20% of areas, mainly Phang Nga, Phuket, Krabi and Trang. Seas around 1 metre, over 1 metre offshore, about 2 metres in storms.
