Rain fell at the highest point on the Greenland ice sheet last week for the first time on record.
Scientists say it is another worrying sign of warming conditions for the ice sheet already melting at a rapid rate.
Temperatures at the ice cap almost never lift above freezing, but officials say they have now done so three times in less than a decade.
In total, seven billion tons of rain fell across Greenland over a three-day period, the largest amount since records began in 1950.
“And they’re an indicator of the bigger effects that we’re starting to see now more and more in the mid-latitudes, things like more fires, more heatwaves, more extreme weather,” said Walt Meier, a senior NSIDC research scientist.
Greenland had a massive melting event in late July, when enough ice melted in a single day to cover the state of Florida in two inches of water.