The Meteorological Department officially announced Thailand's entry into summer on 22 February 2026. Extreme temperatures of 42-43 degrees Celsius are expected, along with warnings for three provinces to be cautious of heat hazards.
At 10:30 a.m. on 19 February 2026, Dr. Sukanyanee Yawichan, Director-General of the Meteorological Department, held a press conference announcing the start of Thailand's summer season for 2026, stating that the country will officially enter summer on 22 February 2026.
Although continuous heat has been observed for several days, the official announcement of summer was delayed until two conditions for summer storms were fully met: firstly, daytime maximum temperatures reaching at least 35 degrees Celsius across more than 60% of upper Thailand, and secondly, sustained winds from a consistent direction.
After the start of summer, upper Thailand—especially the Northeast, Central, and Eastern regions—will face "summer storms." These storms are expected between 23-25 February 2026, so the public is advised to be cautious of potential damage to houses, billboards, and agricultural areas.
Regarding claims that this year's summer storms are influenced by El Niño, the Meteorological Department confirmed that the heat is not related to the ENSO phenomenon, as La Niña conditions currently prevail, shifting toward neutral, with El Niño expected only by August during the rainy season.
It is forecasted that this year's heat will be slightly higher than last year, with average maximum temperatures in upper Thailand at 36-37 degrees Celsius. Some northern areas may experience extreme heat exceeding 42 degrees Celsius. Provinces warned to be cautious of heat hazards include Mae Hong Son, Lampang, and Tak.
Late March to April will be the hottest period of 2026, with sultry and intense heat reaching 42-43 degrees Celsius. Late April to May will bring changing weather, including thunderstorms, unstable conditions, and summer storms.
The Director-General also noted that in the past 75 years, the highest temperature recorded was 44.6 degrees Celsius in Mueang District, Mae Hong Son Province, on 28 April 2016, and again on 15 April 2023 in Mueang District, Tak Province. Last year, the highest temperature reached 42.3 degrees Celsius in Mueang District, Mae Hong Son, on 27 April 2025.
The announced heat levels are based on meteorological measurements, but people may feel hotter due to humidity, which affects the "heat index." Forecasts indicate a high heat index during April-May, so the public is urged to take health precautions against conditions like heatstroke.