Thailand is forecast to enter a hotter‑than‑usual summer later this month, with peak temperatures in some northern provinces likely to climb beyond 42°C, according to the Meteorological Department.
The 2026 hot season is forecast to begin in late February, around two weeks later than normal, and end in mid‑May. Average maximum temperatures across the upper regions are expected to reach 36–37°C, slightly above both the long‑term seasonal norm of 35.4°C and last year’s average of 35.8°C.
The department warned that Mae Hong Son, Lampang and Tak are the most likely to experience extreme heat, with temperatures potentially rising above 42°C during the most intense period of the season.
Conditions will be hot and humid for extended periods, with occasional thunderstorms that may temporarily ease the heat. However, total rainfall is expected to be 30–40% below average, raising concerns about water shortages.
The weather office outlined three phases of summer:
Early to mid‑March: Hot days in many areas; mornings remain cool in the North and Northeast; isolated summer storms possible.
Late March to mid‑April: The hottest spell nationwide, with extreme heat in some provinces, where maximum temperatures may reach 42–43°C. Summer storms may also develop intermittently in the North.
Late April to mid‑May: Transition to the rainy season brings more volatile conditions, with alternating heat and thunderstorms.
