Monday was the hottest day ever recorded on Earth

We Aussies might not have felt it as we shivered through winter, but Monday is going down in the history books as the hottest day ever recorded.

The hottest day on record was recorded this week as the World Meteorological Organization confirmed El Nino is upon us. Picture: WMO

Monday was the world’s hottest day on record, exceeding an average of 17 degrees Celsius for the first time, according to initial measurements taken on Tuesday by US meteorologists.

The average daily air temperature on the planet’s surface on July 3 was logged at 17.01C by an organisation attached to the US National Oceanic and Atmospheric Administration (NOAA).

This measurement surpasses the previous daily record (16.92C) set on July 24 last year, according to data from NOAA’s National Centers for Environmental Prediction going back to 1979.

The world’s average air temperature, which fluctuates between around 12C and just under 17C on any given day over the year, averaged 16.2C at the beginning of July between 1979 and 2000.

The record hot weather was unlikely to be felt by Australians shivering through winter, including a wet day in Sydney on Tuesday. Picture: NCA NewsWire / Nicholas Eagar

The record has yet to be corroborated by other measurements, but could soon be broken as the northern hemisphere’s summer begins.

The average global temperature typically continues to rise until the end of July or beginning of August.

Even last month, average global temperatures were the warmest the European Union’s Copernicus climate monitoring unit had ever recorded for the start of June.

Temperatures are likely to rise even further above historical averages over the next year with the onset of an El Nino weather phenomenon in the Pacific Ocean, which the World Meteorological Organization (WMO) confirmed on Tuesday is now underway. In addition, human activity – mainly the burning of fossil fuels – is continuing to emit roughly 40 billion tonnes of planet-warming CO2 into the atmosphere every year.

El Nino is now underway, the World Meteorological Organization says. Picture: WMO

On Tuesday, the WMO said the 2023 El Nino was now official – the first time it had appeared since 2016.

“The onset of El Nino will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean,” said WMO secretary-general Professor Petteri Taalas.

“Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods,” Prof Taalas starkly warned.

El Nino typically results in parched conditions in Australia.

The WMO said there was now a 90 per cent probability the El Nino would last into the second half of 2023 and would be of at least moderate strength.

El Nino is one extreme of a Pacific Ocean climate driver called the El Nino Southern Oscillation, or ENSO. At the other end of ENSO is La Nina.

During El Nino, the temperature of a specific area of the central and eastern Pacific – called Nino 3.4 in meteorological circles – rises.

This aids in the creation of clouds and rainfall there, rather than over Australia which in turn can lead to drier conditions and drought for the country.

Despite the WMO’s announcement, Australia’s Bureau of Meteorology steadfastly insists the climate driver is not yet upon us.

— with Benedict Brook

Originally published as Monday was the hottest day ever recorded on Earth