Thailand’s Meteorological Department (TMD) says summer 2026 will be hotter than last year, with temperatures in some areas expected to exceed 42°C.
The season is forecast to begin later than usual, around late February, and run through mid-May, with the most intense heat likely between April and May. Northern provinces including Mae Hong Son, Lampang, and Tak are expected to see the highest temperatures.
Average maximum temperatures in northern Thailand could reach 36–37°C, slightly above normal and higher than in 2025. Overall rainfall is expected to be 30–40% below average, although periodic summer storms with thunderstorms, gusty winds, and possible hail may bring brief relief from the heat.
Seasonal Breakdown
March to Mid-April:
Temperatures will steadily rise, with hot daytime conditions across much of the country. Northern and northeastern areas may still see cool mornings early in the season, but heat and humidity will intensify later, with some locations reaching 42–43°C. Summer storms are also likely.
Late April to Mid-May:
Hot weather will continue, but rainfall will gradually increase as winds shift and the southwest monsoon begins, particularly affecting the South.
Southern Thailand
From March to late April, scattered thunderstorms are expected, with generally moderate seas. From mid-April onward, rainfall will increase significantly, especially along the Andaman coast, where heavy downpours and stronger winds are likely. Wave heights could rise to 2–3 meters in the Andaman Sea and 1–2 meters in the Gulf of Thailand.