We have just experienced the hottest day ever recorded on Earth, with average global temperature exceeding 17°C (62.6°F) for the first time.
The average global air temperature recorded 2 metres above Earth’s surface hit 17.01°C (62.62°F) on 3 July, according to data from the National Oceanic and Atmospheric Administration (NOAA) in the US and compiled by the University of Maine.
It beats the record of 16.92°C (62.46°F) reached in August 2016 and July 2022, making 3 July 2023 the hottest ever day on Earth since records began.
Robert Rohde at the University of California, Berkeley, says the spike in temperatures is likely to have been driven by recent heatwaves across the US, Europe and Canada, and accelerating El Niño conditions, which sees sea surface temperatures in the Pacific Ocean rise above average.
“The El Niño event was officially declared by NOAA right at the start of June,” he says. “The warming has been expanding in the Pacific and that is likely to be contributing to things [temperatures] inching up a bit higher in July than in previous months.”
This specific NOAA/Maine data set only goes back to 1979, but it is comparable with other data that goes back much further. Rohde says he is confident that it is the highest ever since instrumental measurements began. It is an “expected milestone”, he says, given the twin drivers of climate change and extra warming from El Niño.
“We will keep passing these thresholds every few years if we have El Niño variability on top of global warming, until we get global warming under control,” says Rohde.
The news comes hot on the heels of a record warm June. Earlier this week, the Met Office, the UK’s national weather service, declared June 2023 to be the hottest on record for the country, with an average mean temperature of 15.8°C (60.44°F) for the month, which is 2.5°C (4.5°F) above average and 0.9°C (1.6°F) above the previous record.
The Met Office said the likelihood of a new June record being set has doubled as a result of climate change. “Alongside natural variability, the background warming of the Earth’s atmosphere due to human-induced climate change has driven up the possibility of reaching record high temperatures,” the agency’s chief meteorologist, Paul Davies, said in a press release.
Meanwhile, data from the EU’s Copernicus Climate Change Service this week confirmed that global average temperatures in June 2023 were 1.46°C above pre-industrial levels, edging ever closer to the 1.5°C threshold countries have vowed not to exceed.
BREAKING: June 2023 has blown away all prior records for the month of June, coming in at a staggering 0.16C above the prior record set in 2019.
It was around 1.46C above the typical temperatures we saw in June in the preindustrial era (1850-1899). pic.twitter.com/7D5yR11n0z
— Zeke Hausfather (@hausfath) July 3, 2023
Global average air temperatures follow the seasonal cycles of the northern hemisphere, with temperatures peaking in July. That is because air temperatures fluctuate more over land than over water, and as the northern hemisphere boasts more land mass than the southern hemisphere, it has a larger influence over the global average.
With El Niño continuing to build through the rest of the year and high summer arriving in the northern hemisphere, Rohde believes it is likely that July and August will also see high – even record – average global temperatures. This year is “more likely than not” to be the hottest year on record, he says.