Marek Kučera 
Exceptional Heat Grips Southeast Asia: June 2025
An intense and early-season heat wave is now affecting large portions of Southeast Asia, with record-breaking temperatures being observed in Laos and Myanmar, countries that are rarely associated with 40°C+ heat in the month of June.
This extreme warmth follows the historic spring heat across South and Southeast Asia and marks a continuation of alarming climate trends in the region.
🇱🇦 Laos: Only the Second Time Over 40°C in June
On June 9, 2025, temperatures soared to 40.5°C in Laos, marking only the second time in recorded history that the country has exceeded 40°C in June.
Such extreme heat is usually confined to April (the traditional hottest month in Southeast Asia), making this June spike very rare and meteorologically significant.
This reading comes amid persistently dry conditions, strong sunlight, and warm air masses spreading across Indochina from the west.
🇲🇲 Myanmar: New All-Time June Record at Nyaunglaybin
On the same day, Nyaunglaybin, located in central Myanmar, recorded 39.0°C, setting a new all-time June temperature record for the station.
This surpassed the previous record for the month, and underscores the widespread nature of this heat event, affecting both inland and upland areas. While Myanmar is no stranger to extreme heat, the timing and spread of this event are unusual.
🔥 Meteorological Context
This heatwave is being driven by:
- A high-pressure ridge extending from the Indian subcontinent into mainland Southeast Asia.
- Subtropical subsidence, or sinking warm air, which suppresses cloud formation.
- Low pre-monsoonal moisture levels, which limit evaporative cooling.
In addition, delays or weakening in the onset of the Southwest Monsoon—common during El Niño or shifting climate phases (e.g., from El Niño to La Niña)—can amplify heat extremes across the region during late May and June.
⚠️ Climate Significance
- These readings are among the hottest June temperatures ever recorded in the region.
- Heat stress and drought risks are rising, especially in agricultural zones, which are sensitive to early-season heat.
- Continued monitoring is needed, as climate models suggest potential for further warming in the coming weeks before monsoon rains fully establish.
Illustration picture: https://www.commondreams.org/media-library/workers-move-blocks-of-ice-into-a-storage-unit-at-a-fresh-market-during-heatwave-conditions-in-bangkok-thailand-on-april-25-2.jpg?
Marek Sadowski