Some seven billion tonnes of rain lashed down between August 14 and 16, in the country’s heaviest deluge since 1950, when records began.

Temperatures on the ice sheet peaked above freezing for the third time in a decade and at the latest date ever seen.

At the sheet’s highest point, 3,216 metres above sea level, rain was recorded for the first time ever by the National Snow and Ice Data Centre.

© REUTERS/Svebor Kranjc A small fishing boat heads out into the sea ice near the town of Uummannaq in western Greenland - REUTERS/Svebor Kranjc

"What is going on is not simply a warm decade or two in a wandering climate pattern," said Ted Scambos, a senior research scientist at the National Snow and Ice Data Centre at the University of Colorado. 

"This is unprecedented. We are crossing thresholds not seen in millennia, and frankly this is not going to change until we adjust what we’re doing to the air," he told CNN.

In a stark illustration of the changing climate, 8.2 million square miles of ice has melted on Greenland already this year.

On August 15, the surface mass lost was seven times above the mid-August average. 

At this point in the year, large areas of bare ice exist along much of the southwestern and northern coastal areas, with no ability to absorb melt water or rainfall. 

Accumulated water on the surface flows downhill and eventually into the ocean, which causes sea levels to rise in the long term.

Greenland’s ice sheet will shrink more this century than at any point in the past 12,000 years, outstripping an earlier period of warming that began 10,000 years ago, scientists predict.

Between 2000 and 2018, the ice sheet shrank at a rate of 6,100 billion tonnes per century, but that rate is set to accelerate to unprecedented levels, a team from the US, Canada and Denmark concluded in a paper, published in the journal Nature, last year.

The cause of the melting event that took place from August 14 to 16 was similar to the events that occurred in late July, where an area of strong low pressure centred over Baffin Island and high air pressure southeast of Greenland conspired to push warm air and moisture rapidly from the south, the National Snow and Ice Data Centre said.