Scientists at the National Snow and Ice Data Center (NSIDC) said that the sea ice cover attained an average maximum extent of 14.52m sq km (5.607m sq miles) on 24 March, the lowest winter maximum since records began in 1979.
The low beats a record set only last year of 14.54m sq km (5.612m sq miles), reached on 25 February 2015.
Scientists say the region experienced "a warm, crazy winter", saying it's part of a long-term trend.
This year's ice didn't break the record by much, but it's "an exclamation point" on a longer-term trend, said Nasa scientist Walt Meier, who helped calculate the data.
To put the record low into perspective, consider that this was 431,000 square miles, or 1.12 million square kilometers below the 1981-2010 average of 6.04 million square miles, or 15.64 million square kilometers. That's about the size of the states of Texas, Arizona and Kansas combined.
"The Arctic is in crisis," said Ted Scambos, lead scientist at the data center. "Year by year, it’s slipping into a new state, and it’s hard to see how that won’t have an effect on weather throughout the Northern Hemisphere.”
This winter was the hottest on record in many places across the globe, with average temperatures 2.03°F (1.13°C) above the 20th century average, according to the National Oceanic and Atmospheric Administration (NOAA).
Temperatures in the Arctic were as much as 16°C (29°F) above average, driving the ice melt. “It’s a lot easier to warm something that’s cold than something that’s already warm,” says Sean Sublette, a meteorologist at Climate Central.
This winter also brought an influx of unusually warm water from the Atlantic. Globally, even though Antarctic sea ice has gotten larger, sea ice has declined overall.