The rate of melt appears to be affected by a factor dubbed Greenland blocking.
The blocking is linked to the high pressure over Canada that influences the northern jet stream, which causes warm air from the US and Canada to reach Greenland.
But the blocking can also have a positive effect on the ice sheet, slowing down the rate of melt in some cases.
This effect was observed in 2017 and 2018 when cooler Arctic air was allowed to flow over Greenland.
In those two years, the ice sheet lost an average of 108 billion tons of ice.
source: express.co.uk