BANGKOK, THAILAND – Thailand’s weather agency warned of a new cold spell in the north and center while heavy rain and rough seas threatened the south.
Temperatures dropped in northern and central regions
From Tuesday, 20 January, to Saturday, 24 January 2026, temperatures in northern and central Thailand were expected to fall by 1 to 3 degrees Celsius. A moderate high-pressure system carrying cold air from China moved across the region and the South China Sea, bringing cool to cold conditions. The Thai Meteorological Department (TMD) advised people in upper Thailand to monitor the changing weather and dress warmly to prevent health problems.
Fog and road hazards in cooler mornings
With the influx of cold air, fog could form particularly in the morning hours. Meteorologists urged all drivers to exercise increased caution on the roads, as visibility could suddenly be severely reduced. These conditions were most likely in mountainous areas and valleys, making careful driving and warm clothing important in the cooler mornings and evenings, even as daytime temperatures remained hot.
Southern Thailand faced intensifying rain and winds
While the north turned cooler, the south faced the opposite extreme. Isolated thunderstorms were forecast for 19 and 20 January, but from Tuesday, 21 January, the situation was expected to become more serious as the northeast monsoon strengthened to a moderate level. This was set to bring more rain, stronger winds and increasing wave heights, with seas in the lower Gulf of Thailand forecast to reach 1 to 2 meters.
Maritime warning for ships and island tourists
For the Gulf of Thailand and the Andaman Sea, the TMD issued a warning for ships, noting that waves near thunderstorms could exceed 2 meters. Small boats were urged to avoid these areas, and the conditions required particularly cautious navigation. For tourists on islands in the south, the authorities stressed that weather could change rapidly, so beach trips and boat excursions should be carefully planned and official warnings strictly followed.
Contrasting weather across the country
The situation highlighted Thailand’s climatic diversity, with sweaters coming out around Chiang Mai while holidaymakers in Phuket or Koh Samui had to prepare for showers. The pattern was typical for the season but could still lead to flooding in the south and health problems for vulnerable people in the cooler north.
“Cold fronts remind us every year how vulnerable daily life, health and infrastructure really are.”
said The Nation, media outlet.
Questions over preparedness and climate risks
“Are authorities and the public prepared for sudden weather changes?”
said The Nation, media outlet.
“Or is nature in Thailand still underestimated as long as it does not strike in a spectacular way?”
said The Nation, media outlet.
“What does climate change mean when extremes become the new normal?”
said The Nation, media outlet. The TMD urged the public to stay up to date with its latest forecasts to be ready for both colder conditions in the north and storms in the south.