However, the centre cautioned that the figures were preliminary, adding that changing winds could still push the ice extent lower.
Ted Scambos, NSIDC lead scientist, commented: "It really suggests that in the next few years, with more typical warmer conditions, we will see some very dramatic further losses."
This year's minimum is seen as something of a surprise as scientists believed that the low atmospheric pressure and cloudy skies in June and July had slowed down the melt.
"It's pretty remarkable that this year's sea-ice minimum extent ended up the second lowest, after how the melt progressed in June and July," said Walt Meier, a sea ice scientist with Nasa's Goddard Space Flight Center.