Antarctic ice at record high, but Arctic below average

Though the amount of sea ice at the Antarctic should set an all-time record high this month, Arctic ice shrank to its sixth-lowest level on record, scientists from the National Snow and Ice Data Center reported this week.

September is the month when Antarctic ice usually reaches its highest extent of the year, at the end of the Southern Hemisphere winter. It's also when Arctic ice typically reaches its annual minimum, as our summer draws to a close.

Sea ice is frozen ocean water that melts each summer, then refreezes each winter.

"Antarctic sea ice is poised to set a record maximum this year, now at 7.6 million square miles and continuing to increase," the ice center noted on its website. Sea ice data goes back to 1979, when satellites first began to measure it, USA Today reports.