Over the past week, Greenland's highest point saw rain instead of snow, for the first time on record.
Hours of rain poured down at the ice sheet's 3,200-metre summit, as scientists with the US National Snow and Ice Data Centre witnessed temperatures above freezing for nine hours.
Senior scientist Walt Meier says it's a rare sight.
"We have atmospheric data that we can infer conditions and that there hasn't been any rain since those records began in 1950. So it's, in our records, it's a unique situation."
Seven billion tonnes of rain fell across Greenland within a three-day period the past week.
It's also the largest amount on record.
Higher temperatures have also triggered the warming of ice sheets, which experts say are melting faster.
Ice loss on August 15, triggered by rain and high temperatures, was seven times above average for mid-August.
"You raise temperatures a couple degrees in the mid latitudes, it's something you don't maybe notice even. But raising it from one degree below freezing to one degree above freezing is the difference, if you're in the Arctic Ocean, it's a difference between ice skating and swimming."
The record-breaking rain is the latest in a string of warnings on how climate change is affecting Greenland's ice sheet.
A massive ice-melt in July saw enough water released to cover an area the size of Florida, in two inches of water.
The latest UN report on climate change said the Arctic region is expected to warm at least twice as fast as the global average, and that it is "unequivocal" that human activity has caused global warming.