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Thailand's cold season is expected to start around the third week of October 2026, about a week later than usual, and run until roughly mid-February 2027. The Thai Meteorological Department (TMD) expects it to be milder than normal, with nationwide average minimum temperatures about 2°C above normal. Rain is the bigger travel factor in the short term, with a separate heavy rain warning covering 18 to 25 October and a heavy rain risk along the Gulf coast in November and December.
When the cold season starts and ends
According to TMD's seasonal outlook, released on 15 October 2026, the cold season should begin around the third week of October. That is roughly a week later than normal. It is expected to continue until about mid-February 2027.
How cold will it get?
Don't expect a proper winter in most places. The national average minimum temperature is forecast at 22 to 23°C, which is about 2°C above normal, so the season overall is expected to be warmer than usual.
The lows vary by region:
| Region | Expected lows |
|---|---|
| Upper North and upper Northeast | 10 to 12°C |
| Bangkok | 19 to 21°C |
| Bangkok surroundings | 18 to 20°C |
The coldest stretch is expected from late December to early February. Mountain summits and ridges may see cold to very cold conditions, and there may be frost in some areas. If you are heading to the north or northeast in that window, pack layers.
Why it's warmer this year
TMD attributes the warmth to El Niño. It is expected to strengthen toward the end of 2026 and continue into early 2027.
Rain and sea conditions in the south
TMD warns of possible heavy rain along the Gulf coast from Chumphon southward in November and December. The risks include flash floods, runoff and overflowing rivers.
For the Gulf, waves of 2 to 4 m are forecast, and storm surges of 4 to 5 m are possible in some locations. If you are travelling around the Gulf islands such as Samui, Phangan and Tao, ferry delays or cancellations are plausible. The article refers to the Gulf coast and does not specify the Andaman side.
Given the flash flood risk in the south in November and December, flexible bookings and travel insurance are sensible.
Thunderstorms in January and February
In January and February, the upper part of the country may see thunderstorms, squalls and hail in places.
A separate heavy rain warning for 18 to 25 October
TMD issued a short-term warning on 18 October for heavy to very heavy rain between 18 and 25 October. This is separate from the cold-season outlook and may change.
- 18 to 20 October: persistent rain in the South and East, with heavy to very heavy falls in some areas.
- 21 to 25 October: rain increases across the lower Northeast, Central Thailand (including Bangkok and the metro area), the East and the upper South. Occasional gusty winds are possible.
That week is wet for the South, Bangkok and the East, so expect some disruption and keep your itinerary flexible.
How reliable is the outlook?
The outlook is based on statistical data and climate models, and it is provisional. TMD plans an update in the last week of October.
Information sourced from The Thaiger.