Heatwaves affecting large tracts of the Northern Hemisphere are expected to last into August, the World Meteorological Organisation (WMO) has said.
Climate change also means future heatwaves will become more frequent and be spread across more months, said John Nairn, the WMO’s senior extreme heat adviser.
As southern Europe grapples with successive heatwaves during the peak tourist season, local and national authorities have warned of increased risks to health, potentially even deaths.
Extreme weather has disrupted the lives of millions of people in America, with dangerous heat stretching from Southern California to the Deep South. Asian countries such as China and Middle East countries have also recorded regional temperature surges. The UAE recorded its first 50ºC day of the year last weekend.
More than 61,000 people died from heat-related causes during the summer last year, a comprehensive study published in Nature Medicine journal found.
“We should expect or at least plan for these extreme heatwaves to continue through August,” Mr Nairn said.
“We're on trend in seeing a rise in global temperatures that will contribute to heatwaves increasing in intensity and frequency,” Mr Nairn said.
“We've got quite clear indications that they're already growing out into spring.”
Across southern Europe locals and tourists are being warned to be aware of the dangers that the heat poses.
A second heatwave hit Greece as firefighters struggled to contain a wildfire west of Athens that has burnt forests for a fifth day.
More than 100 houses and businesses have been severely damaged by this fire and another near Athens that authorities put out earlier in the week.
Two other blazes in forests on the island of Rhodes and in the Lakonia district in southern Greece were tamed on Friday.
Italy and Spain have also endured unusually hot temperatures that sparked wildfires.
Soaring temperatures are being fuelled by an anticyclone, or area of high air pressure, named Charon after the ferryman of the dead in Greek mythology.
The weather system pushed into the region from North Africa at the weekend, following Cerberus, another anticyclone, which caused extreme temperatures in the same part of the continent last week.
The EU's Copernicus Climate Change Service says 2022 and 2021 were the continent's hottest summers on record. Europe's highest recorded temperature of 48.8ºC was registered in Sicily two years ago.
Heat records are being shattered the world over, and scientists say there is a good chance that 2023 will go down as the hottest year on record, with measurements going back to the middle of the 19th century.
June recorded the warmest global average temperature, according to Copernicus, and the WMO predicted that several records were likely to be broken this summer.
The global organisation said unprecedented sea surface temperatures and low Arctic sea-ice levels were largely to blame.
Human-caused climate change is making the world hotter and is being amplified by the naturally occurring El Nino weather phenomenon.
But the current El Nino started only a few months ago and is still weak to moderate. It is expected to peak during winter.