BANGKOK, THAILAND – A brief warm spell across Thailand gave way to official warnings of thunderstorms, fog and heavier rain from Thursday onward.
Temperatures rose before conditions shifted
On Wednesday, 3 December, temperatures across upper Thailand rose by 1–2 degrees Celsius, bringing a noticeable warming trend. The north and northeast nevertheless remained cool to cold in the morning, with light fog forming in many parts of the country. Bangkok and surrounding areas also started the day with a hazy morning before conditions turned somewhat warmer.
New cold air mass triggers storms and rain
The calmer weather was short-lived, as conditions were forecast to change markedly from Thursday, 4 December, through Saturday, 6 December. A new, moderately strong cold air mass from China moved across Vietnam and Laos toward Thailand, bringing moist easterly winds. As a result, upper Thailand was expected to see isolated showers and thunderstorms, while the south was told to prepare for intensified rainfall.
Regional forecast: fog, showers and temperature spread
According to the Thai Meteorological Department (TMD), Bangkok could expect light morning fog, with minimum temperatures of 23–25°C and maximums of 33–35°C on Thursday. In the north, conditions were forecast to be cool to cold with morning fog, ranging from 14–20°C at night and 30–34°C during the day, and just 5–15°C on mountain areas. The northeast was predicted to remain cool at 16–22°C overnight and 31–34°C during the daytime, while central Thailand was set for cool, foggy conditions with 19–22°C in the morning and 33–35°C later in the day.
Southern coast facing more rain
Along the southern Gulf coast, the TMD expected scattered light showers. Minimum temperatures there were forecast at 21–24°C, with daytime highs between 31–34°C. The agency indicated that residents in the south should be ready for periods of stronger rain as the moist air from the cold front fed into local weather systems.
Health and safety calls from authorities
Authorities urged the public to pay attention to the changing conditions and to dress appropriately for cooler mornings and wetter periods. They also continued to warn of elevated fire risk despite the incoming rain, citing ongoing dryness in many areas. Motorists were asked to exercise particular caution in foggy areas and to adjust their speed to the reduced visibility.
Implications for tourists and outdoor plans
For visitors, the unsettled pattern meant flexibility was essential when planning trips and outdoor activities. Officials recommended that tourists plan excursions early and consult weather apps regularly for updates. Thunderstorm potential was described as a key risk factor, especially for boat tours and mountain hikes, where rapidly changing conditions could increase danger.
December proves unpredictable
The brief warming at the start of the month underlined how volatile Thailand’s December weather could be. The mix of foggy roads, distant lightning and damp urban conditions showed that the season still held the potential for sudden swings. These shifts raised questions for some observers about how resilient Thailand would need to become in the face of increasingly erratic weather patterns.