The United Arab Emirates registered a sizzling 50.4 degrees Celsius on Friday, the highest on record for May, following weeks of sweltering temperatures in the desert nation acutely vulnerable to climate change.

Worshippers at Friday prayers reported feeling faint and some residents appeared unsteady on their feet, even in a country that is accustomed to extreme temperatures.

The highest temperature was recorded in an area of Abu Dhabi, the capital of the oil-rich Gulf state that lies in one of the world's hottest regions.

"The weather was extremely hot today, unbearably so," said one 26-year-old Abu Dhabi resident, who said he arrived at the mosque late and had to pray outside.

"I was drenched in sweat by the end of the prayers," he said, preferring not to give his name, adding that he felt like he was "about to faint."

The high temperature of 50.4°C (122.7 Fahrenheit) is the hottest in May since records began in 2003, outstripping the 50.2°C seen in 2009, said the National Centre of Meteorology.

The UAE, one of the world's biggest oil exporters and host of the Cop28 climate talks in 2023, has just emerged from a record-breaking April with an average daily high of 42.6 degrees Celsius. (AFP)