BANGKOK, THAILAND – A leading climate economist warned that Thailand had already entered the mid-phase of El Niño and could face escalating impacts until at least early 2027.
El Niño phase advancing earlier and lasting longer
Dr Witsanu Attavanich, Associate Professor of resource, environmental and climate change economics at Kasetsart University, said on 16 February 2026 that the country was now in the “mid-phase” of El Niño and was likely to move into a fully developed state by May 2026.
He estimated that the event could last at least until February 2027, meaning it would take effect earlier and persist longer than previously assumed.
Rising heat and uneven drought risks across regions
Dr Witsanu cautioned that the transition to a strong El Niño would raise risks from heat hazards, dry spells and more erratic rainfall in several parts of the country.
For the hot season from March to May 2026, above-average temperatures were expected nationwide, with unusually high heat likely to persist until at least August 2026.
South and lower East face heightened heatwave threat
The expert viewed the risk of heatwaves in the South and the lower eastern region as particularly critical, saying these areas needed closer monitoring than other parts of the country.
Forecasts also indicated that from May to July 2026 dry periods could affect not only the South but also the upper North and parts of the Northeast.
Global models point to similar El Niño pattern
According to ECMWF data cited by Dr Witsanu, Thailand was already in the mid-phase and was expected to enter El Niño conditions in May 2026, with a possible strengthening in November 2026 to a moderate to strong level lasting into early 2027.
At the same time, models from NOAA in the United States showed the same trend towards El Niño but put the probability of a strong event between September and November 2026 at only 14 percent, underlining uncertainty over its exact intensity.
Outlook to August 2026: hotter overall, wetter pockets in the West
Several model runs suggested that from March to August 2026 temperatures would remain above the long-term average nationwide, with a heightened risk of heatwaves especially from March to May.
From June to August, however, the West and the lower North, including provinces such as Tak and Kanchanaburi, as well as Kamphaeng Phet, Nakhon Sawan, Uthai Thani and Suphan Buri, could see above-average rainfall.
Early signs of weaker rain at the start of the wet season
Supplementary data from the IRI at Columbia University indicated, according to Dr Witsanu, that some regions could already see the first signs of declining rainfall between March and June 2026.
This tendency was expected to become clearer from May to July and pointed to an increased risk of dry spells at the beginning of the rainy season.
Near-normal February rain but mounting planning pressure
For February 2026, the economist expected overall nationwide rainfall to be close to the long-term average, meaning the current dry season did not necessarily have to be exceptionally severe.
At the same time, he stressed that water management still needed to be planned in advance so that storage and distribution were adjusted in time for the coming months.
Health, energy and agriculture in the firing line
Dr Witsanu noted that higher temperatures could increase health risks, energy costs and water demand, while dry spells could hurt agricultural yields, farmers’ incomes and long-term food security.
From a resource economics perspective, he said early planning of water allocation was crucial, including reservoir management, irrigation control and crop planning adapted to increasingly variable conditions.
Call for early preparation and close monitoring
“Thailand should start preparing for heat and drought from today and closely follow the forecasts.”
said Dr Witsanu Attavanich, climate economist at Kasetsart University.
He added that new models could provide increasingly precise and continuously updated projections, and that planning must ensure sufficient water availability into next year and encourage actors in all sectors to closely observe developments in an era of climatic upheaval.