Greenland's massive ice sheet has started melting unusually early this season thanks to warm temperatures and rain.

Scientists reported that nearly 12 percent of the ice sheet surface area - 656,000 square miles - showed signs of melting ice on Monday and Tuesday. This much melting is generally not seen until late May.

"It's nothing for July, it's huge for April," said Peter Langen, a climate scientist at the Danish Meteorological Institute. "It's disturbing. Something like this wipes out all kinds of records, you can't help but go this could be a sign of things we're going to see more often in the future."

The previous record for a melt of more than 10 percent was set on May 5, 2010. What's more is that this year marks the first time the ice sheet has started melting in April.

A recent analysis of Greenland's unseasonable melt revealed that cold air and low pressure systems to the east and west of the ice sheet have forced a warm air "cap" over the island. Above freezing temperatures coupled with rain have therefore helped melt the ice. 

"We had to check that our models were still working properly," Langen added.

However, temperature readings of the ice showed some places exceeded 10 degrees Celsius, confirming that the spring thaw had gotten an early start. 

The village of Kangerlussuaq in southwest Greenland reached highs of 17.8 degrees Celsius on Monday, which is an April record for that area and only 0.2 degrees short of an all-time high for Greenland in April. Another record was set in Nuuq, Greenland's capital, where temperatures fell just short of 17 degrees Celsius on Monday.  

While part of the warming can be attributed to Earth's natural weather system, man-made climate change has worsened it. 

"Things are getting more extreme and they're getting more common. We're seeing that with Greenland and this is an indication of that," said Walt Meier, an ice scientist from NASA. "This kind of freakish warm spell is another piece in the puzzle. One freakish thing every once in a while you might expect. But we're getting these things more often and that's an indication of climate change."

With the ice sheet melting faster than ever predicted, scientists are most concerned about subsequent sea level rise. 

While it will take centuries for the entire Greenland ice sheet to melt, within the next 100 years or so, sea level could rise by a couple feet. 

Greenland can expect to see this recurring pattern, as the majority of the meltwater sitting on top of the ice sheet will likely percolate into the snow and refreeze. This, in turn, will carry heat energy to lower depths and reduce the amount required to thaw the ice later.