"The highest temperature recorded over the country today is 51.6C in Sweihan (Al Ain) at 13:45 UAE local time (0945 GMT)," the National Center of Meteorology said in a post on X, just 0.4C off the overall heat record in the Gulf country.

The meteorology office told AFP the highest ever temperature recorded in the UAE since documentation began in 2003 was reported at 52C on Abu Dhabi's Al Yasat Island in 2010.

The desert nation, a top global oil exporter, lies in one of the planet's hottest regions and one which is particularly vulnerable to climate change.

The temperature in Sweihan -- which lies 97km (60 miles) west of Abu Dhabi -- and of 50.4C a day earlier in the Emirati capital exceeded the previous record for May of 50.2 Celsius recorded in 2009, according to the meteorology office.

On Saturday in Dubai, where high temperatures in the mid-40 degrees Celsius were recorded, motorists complained air conditioning in their cars was struggling to stifle the sweltering heat, surprised the phenomenon had hit so early in the year.

On the streets, Dubai inhabitants were still out and about -- some armed with parasols -- and vendors selling water and local juice bars appeared to enjoy an uptick in customers.

The UAE, 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.

- Extremely hot days -

Scientists have shown that recurring heatwaves are a clear marker of global warming and that these heatwaves are set to become more frequent, longer and more intense.

The number of extremely hot days has nearly doubled globally in the past three decades.

Outdoor workers in Arab states face some of the highest exposure to heat stress in the world, with 83.6 percent suffering from excessive heat exposure on the job, according to a 2024 report from the International Labour Organization, a United Nations agency.

The risks from a warming planet were on stark display last June, when more than 1,300 people died while performing the annual Muslim hajj pilgrimage to Mecca in neighbouring Saudi Arabia, according to an official tally -- most of them unauthorised pilgrims exposed to long periods outdoors.

According to a 2022 Greenpeace study, the Middle East is at high risk of water and food scarcity as well as severe heat waves as a result of climate change.

The report, which focused on six countries including the UAE, found the region was warming nearly twice as fast as the global average, making its food and water supplies "extremely vulnerable" to climate change.