Thailand braces for dangerous extreme heat before Songkran

Thailand is bracing for dangerous heat in the lead-up to Songkran 2026, with temperatures in several areas expected to climb above 42°C, prompting warnings over health risks during one of the busiest outdoor periods of the year.

Assessments show that between April 8 and 9, 2026, temperatures in many parts of the country could rise sharply, with parts of the North and Upper Central forecast to reach 40-43°C, a level considered a significant threat to health.

Dr Sonthi Kotchawat, an environmental and health expert from the Thai Environmental Academic Club, said data from the Thai Meteorological Department points to an abnormal warming trend in early April.

According to the assessment, the North and Upper Central could see highs of 40-43°C, Bangkok and surrounding areas are expected to range from 35-41°C, while the South could record temperatures of around 34-39°C.

Extreme heat poses rapid health risks

Experts warn that these temperatures fall into the category of extreme heat, which can affect the body quickly, especially during prolonged exposure or in poorly ventilated surroundings.

Research by Dr Fiona Rennie, a family medicine physician at Valiant Clinic in the UAE, indicates that spending just one hour in extreme heat can significantly disrupt bodily functions. Even a slight rise in core body temperature can lead to fatigue and put stress on multiple systems.

At temperatures of 39-40°C, brain function may slow, breathing can become rapid, exhaustion may set in and organ efficiency may begin to decline. At 40-41°C, the risk rises to acute physical exhaustion and an immediate need for rest, with a high chance of heat exhaustion.

Once temperatures move beyond 41°C, the body may start to lose its ability to regulate internal temperature, increasing the risk of heat cramps, severe heat exhaustion, rapid heartbeat, heavy sweating and potentially heat stroke, which is a life-threatening emergency. At around 50°C, conditions approach the upper limit of human tolerance, with a serious risk of acute heart failure.

Heat brings wider economic and environmental strain

The recurring extreme heat also reflects the growing frequency of extreme weather events. In Thailand, such conditions typically peak late in the summer before the monsoon season, when stagnant air masses trap heat close to the surface.

Beyond its effects on health, the heat can also weigh on the economy. Higher temperatures drive up electricity demand for air conditioning, reduce productivity among outdoor workers and increase the risk of crop damage.

Cities are also likely to feel the impact more severely because of the urban heat island effect, where concrete and asphalt surfaces absorb and retain heat, pushing temperatures above those in rural areas.

Elderly, children and outdoor workers face greater danger

Those most at risk include elderly people, young children, individuals with chronic illnesses such as heart disease, hypertension and respiratory conditions, as well as outdoor workers including construction workers, farmers and field staff.

Extreme heat can cause the body to lose vital fluids and minerals quickly, which may lead to dizziness, fainting or loss of consciousness if hydration is not maintained.

Experts advise avoiding outdoor activities between 9am and 3pm when temperatures rise above 38°C, as this is the period when solar radiation is at its strongest.

People are encouraged to drink at least two litres of water a day, wear light and breathable clothing, use hats and UV400 sunglasses, and apply sunscreen with SPF 30 or above to reduce long-term skin damage. Alcohol, caffeine and high-sugar drinks should be avoided because they can speed up dehydration. Staying in well-ventilated or air-conditioned spaces and sipping cool water regularly can also help reduce risk.

Songkran preparations may increase exposure

The period before Songkran typically involves heavy outdoor activity, including travel, house cleaning and festival preparations, which may raise the risk of heat-related illness.

To stay safe, experts recommend planning activities for the early morning or late evening rather than the hottest part of the day. Symptoms such as nausea, unusual sweating or a rapid pulse should be treated as warning signs that require immediate attention.

The growing frequency of extreme weather has also reinforced calls for better urban planning, including more green spaces, heat-efficient building design and stronger heatwave warning systems.

The extreme heat expected in April 2026 is a fresh reminder for people across Thailand to stay alert and prioritise their health as the country moves into the hottest stretch of the year.