Washington DC - Monday was the world's hottest day on record, exceeding an average of 62.6 degrees Fahrenheit 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 62.62 degrees Fahrenheit by an organization attached to the US National Oceanic and Atmospheric Administration (NOAA).

This measurement surpasses the previous daily record of 62.4 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 54 and just under 63 degrees on any given day over the year, averaged 61 degrees at the beginning of July between 1979 and 2000.

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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 the 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 Niño weather phenomenon in the Pacific Ocean, which the World Meteorological Organization confirmed on Monday 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, which is by orders of magnitude too much to stop temperatures from rising to catastrophic levels by the end of the century.