The El Nino weather pattern will bring a hotter and drier climate across Thailand in the coming months, say climate experts.

Even though very hot and humid weather is expected at this time of year, heatwaves during this summer have been more extreme than anticipated, with a new high-temperature record of 45.4 degrees Celsius being measured in Tak on Saturday.

In response, experts have called on Thai authorities to urgently respond to the issue as more than 80% of the population has already been affected by unbearably hot weather and water shortages.

An expert at Kasetsart University, Asst Prof Witsanu Attavanich, said what the kingdom is experiencing is due to human-induced climate change.

He said the impact of greenhouse gas emissions from human activities had been gradually raising the global mean temperature since the industrial revolution, increasing the extreme heat in Thailand.

He said it is highly likely that this year's extreme heat will continue even after summer ends due to the warming effects of the developing El Nino phenomenon.

Therefore, he expected that there will be less rain this rainy season.

Dr Thiravat Hemachudha of the Thai Red Cross also raised concerns about Thailand's climate becoming hotter.

He said that more people would be exposed to heatstroke, which can be deadly.

He explained that heatstroke mostly occurs in hot and humid weather. If the body cannot regulate the internal temperature, the body's core temperature will go beyond 40 degrees Celsius, which can seriously damage bodily functions and lead to disability or death.

Tara Buakamsri of Greenpeace Southeast Asia said this year's sizzling summer is a clear result of climate change.

"Even though Thai people are familiar with a hot climate, such heat, over 40 degrees Celsius, can cause serious health issues from overheating, especially given Thailand's relatively high humidity, which can accelerate the heat index and makes it feel hotter," he said.

Mr Tara called on the authorities and policymakers to prioritise preparing the country to cope with the approaching climate challenges and take action towards mitigating climate change.