The average daily air temperature on the Earth's surface reached 17.18 degrees Celsius, according to data compiled by an organization attached to the U.S. National Oceanic and Atmospheric Administration, NOAA.
That far outstripped even the previous day's record measurement, when the average global temperature reached 17.01 degrees Celsius. That surpassed the August 2016 record of 16.92 Celsius as heatwaves sizzled around the world.
That topped the previous daily record of 16.92 Celsius dating to July 24, 2022.
For comparison, the world's average air temperature, which fluctuates between 12 Celsius and just under 17 Celsius on any given day over the year, averaged 16.2 degrees at the beginning of July from 1979 to 2000.
This reported record has yet to be corroborated by other measurements, but could be broken again as the northern hemisphere's summer begins.
The E.U. climate monitoring unit Copernicus confirmed in a statement to AFP on Wednesday that Monday had been the hottest day in its dataset going back to 1940. It could not yet confirm the data for Tuesday.
The average global temperature typically continues to rise until the end of July or early August.
Even last month, average global temperatures were the warmest Copernicus had ever recorded for the start of June.
The southern United States has been suffering under an intense heat dome in recent weeks. In China, an enduring heatwave continued, with temperatures above 35C. North Africa has seen temperatures near 50C.
And even Antarctica, currently in its winter, registered anomalously high temperatures. Ukraine's Vernadsky Research Base in the white continent's Argentine Islands recently broke its July temperature record with 8.7C.
"This is not a milestone we should be celebrating," said climate scientist Friederike Otto of the Grantham Institute for Climate Change and the Environment at Britain's Imperial College London.
"It's a death sentence for people and ecosystems."
Scientists said climate change, combined with an emerging El Nino pattern, were to blame.
"Unfortunately, it promises to only be the first in a series of new records set this year as increasing emissions of [carbon dioxide] and greenhouse gases coupled with a growing El Nino event push temperatures to new highs," said Zeke Hausfather, a research scientist at Berkeley Earth, in a statement.
This report was compiled from Reuters and Agence France-Presse
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