The hottest air temperature recorded anywhere on the planet in at least at century, and possibly ever, was reached in Death Valley in California's Mojave Desert on Sunday afternoon where it soared to 54.4 degrees Celsius (130 Fahrenheit).
An automated observation system run by the U.S. National Weather Service at Furnace Creek reported the record at 3:41 p.m. local time.
It was a dry heat: humidity fell to 7%. But it felt "insanely hot" all the same, according to meteorologist Daniel Berc, who is based in the NWS Las Vegas bureau and forecast that the heatwave would continue all week.
"It's literally like being in an oven," he said in a telephone interview. "Today is another day we could take another run at 130F."
A temperature of 56.7 degrees Celsius (134F) was recorded in Death Valley in July 1913. Some meteorologists dispute the older record, however, with recent research pointing to the likelihood it was the result of observer error.
"That's an official record until it's debunked through the scientific process and accepted by the World Meteorological Organization," Berc said.
The record comes as climate scientists warn of the dangers of a warming planet. Last month was the world's third-hottest July on record, and three of the hottest ever Julys all occurred within the last five years.
Sunday's temperature will undergo a formal review, Berc said. Technicians will check the thermometer out in Furnace Creek is working properly. The NWS will convene a so-called climate extremes committee to ensure there's no reason to doubt Sunday's data.