Cool spell holds in upper Thailand; monsoon to strengthen over south
Upper Thailand will remain cool with light morning mist and slightly higher daytime temperatures, while lower South is expected to see heavier rain later this week, especially during December 25–28.
- Upper Thailand will remain cool due to a persistent cold air mass, with minimum temperatures around 15°C and frost possible on some mountain tops.
- The northeast monsoon over southern Thailand is currently weak but is forecast to strengthen significantly from December 25-28.
- The strengthening monsoon is expected to bring increased rainfall to the south, with warnings for heavy to very heavy rain and hazardous sea conditions in the lower South.
The Thai Meteorological Department’s weather forecast for Wednesday (December 24) says upper Thailand will remain cold as a cold air mass continues to cover the area, with the lowest temperatures around 15°C.
Bangkok will be cool with light morning mist, while the South will see more rainfall.
24-hour forecast outlook
Over the next 24 hours, upper Thailand will see a slight rise in temperatures, but it will remain cool with light morning mist as the high-pressure system (cold air mass) covering upper Thailand and the South China Sea weakens.
Mountain tops will be cold to very cold, with frost in some areas, while highland peaks will be cold.
People are advised to take care of their health as the weather changes.
In the South, rainfall will remain limited, though there may still be isolated thunderstorms in the lower South, as the northeast monsoon over the Gulf of Thailand and the South remains weak.
In the lower Gulf, waves will be around 1–2 metres, and over 2 metres in thunderstorm areas.
Mariners in the Gulf of Thailand and the Andaman Sea should proceed with caution and avoid sailing in thunderstorm areas.
Weather warning
During December 25–28, 2025, the South is expected to see increased rainfall, with heavy to very heavy rain in some areas of the lower South, as the northeast monsoon strengthens over the Gulf of Thailand, the South and the Andaman Sea.
Residents in the lower South should beware of hazards from heavy rain and accumulated rainfall.
Forecast for Thailand 6am Wednesday (December 24) to 6am Thursday (December 25)
Bangkok and vicinity
- Partly cloudy with light morning mist; temperatures to rise slightly.
- Minimum: 23–25°C
- Maximum: 33–35°C
- Northeast winds 10–20 km/h
Northern region
- Cool to cold with morning mist.
- Minimum: 15–21°C
- Maximum: 28–34°C
- Mountain tops: cold to very cold with frost in some places.
- Minimum (mountain tops): 4–12°C
- Easterly winds 10–15 km/h
Northeastern region
- Cool with light morning mist.
- Minimum: 18–22°C
- Maximum: 31–34°C
- Highland peaks: cold.
- Minimum (highland peaks): 10–14°C
- Northeast winds 10–20 km/h
Central region
- Cool with light morning mist; temperatures to rise slightly.
- Minimum: 19–23°C
- Maximum: 33–34°C
- Northeast winds 10–20 km/h
Eastern region
- Cool with light morning mist; temperatures to rise slightly.
- Minimum: 20–25°C
- Maximum: 33–35°C
- Northeast winds 15–30 km/h
- Sea waves around 1 metre
Southern region (east coast)
- Cool in the morning in the upper South, with thunderstorms in 10% of the area, mainly in Songkhla, Pattani, Yala and Narathiwat.
- Minimum: 20–24°C
- Maximum: 32–34°C
- From Nakhon Si Thammarat northwards: northeast winds 15–30 km/h, waves around 1 metre
- From Songkhla southwards: northeast winds 15–35 km/h, waves 1–2 metres, and over 2 metres in thunderstorm areas
Southern region (west coast)
- Cool in the morning in the upper South, with light rain in some areas of the lower South.
- Minimum: 21–24°C
- Maximum: 32–34°C
- Northeast winds 15–30 km/h
- Sea waves around 1 metre; offshore waves over 1 metre
