Meteorological Dept warns of higher PM2.5, predicts warmer weather in next seven days
TMD forecasts temperatures rising 1–4°C in Upper Thailand on Jan 26–31, with morning fog and higher risk of PM2.5 build-up. Seas gradually ease.
The Thai Meteorological Department (TMD) has forecast warmer conditions over the next seven days, warning that poor air ventilation and light winds could worsen dust accumulation in Upper Thailand.
In its outlook for January 26–31, 2026, the TMD said temperatures in Upper Thailand and the upper South are expected to rise by 1–4°C, with morning fog. However, it will remain cool to cold in the mornings in parts of the upper North and upper Northeast, as the high-pressure system (cold air mass) covering Upper Thailand and the South China Sea weakens. The South may still see isolated thunderstorms.
Monsoon persists; waves expected to ease
A moderate northeast monsoon will continue to prevail over the Gulf of Thailand, the South and the Andaman Sea, while winds and waves are expected to weaken. In the lower Gulf of Thailand, waves are forecast at 1–2 metres, rising to over 2 metres in thunderstorm areas.
Health and marine advisories
The TMD advised people in Upper Thailand and the upper South to take care of their health due to changing weather conditions.
It also warned that PM2.5 may increase in Upper Thailand during January 26–31 as conditions limit vertical air movement and winds remain light.
Mariners in the Gulf of Thailand and the Andaman Sea were advised to navigate with caution and avoid sailing in thunderstorm areas.
Regional forecast: 6pm today to 6pm tomorrow
North
Cool to cold with light morning fog; temperatures rising 1–2°C.
Min: 13–18°C | Max: 29–33°C
Mountain tops: cold to very cold; frost in some areas. Min: 2–12°C
Easterly winds: 10–15 km/h
Northeast
Cool to cold with light morning fog; temperatures rising 1–2°C.
Min: 13–19°C | Max: 29–33°C
Mountain tops: cold. Min: 8–14°C
Northeasterly winds: 10–15 km/h
Central
Cool with light morning fog; temperatures rising 1–2°C.
Min: 16–19°C | Max: 31–33°C
Easterly winds: 10–15 km/h
East
Cool with light morning fog; temperatures rising 1–2°C.
Min: 18–23°C | Max: 31–35°C
Easterly winds: 15–35 km/h
Sea: waves around 1 metre; 1–2 metres offshore
South (East coast)
Cool in the morning; temperatures rising 1–2°C in the upper South.
Thunderstorms in 10% of the area, mainly in Chumphon, Surat Thani, Nakhon Si Thammarat and Songkhla.
Min: 17–24°C | Max: 29–32°C
From Surat Thani northwards: NE winds 15–35 km/h; waves 1–2 metres (over 2 metres in storms)
From Nakhon Si Thammarat southwards: NE winds 20–35 km/h; waves around 2 metres (over 2 metres in storms)
South (West coast)
Cool in the morning; thunderstorms in 10% of the area, mainly in Krabi, Trang and Satun.
Min: 21–24°C | Max: 32–34°C
NE winds: 15–35 km/h
Sea: waves around 1 metre; 1–2 metres offshore (over 2 metres in storms)
Bangkok and vicinity
Cool with light morning fog; temperatures rising 1–2°C.
Min: 21–23°C | Max: 32–35°C
Easterly winds: 10–15 km/h
