Scientists at the US National Snow and Ice Data Center said data showed that the sea ice extent was tracking below the previous record low, set in 2007.
Latest figures show that on 13 August ice extent was 483,000 sq km (186,000 sq miles) below the previous record low for the same date five years ago.
The ice is expected to continue melting until mid- to late September.
"A new daily record... would be likely by the end of August," the centre's lead scientist, Ted Scambos, told Reuters.
"Chances are it will cross the previous record while we are still in ice retreat."
Sea ice extent refers to a measurement of the area of Arctic Ocean that contains at least some sea ice. Areas with less than 15% are considered by scientists to mark the ice edge.
In its latest summary, the centre said the average rate of ice loss since late June had been "rapid", with just over 100,000 sq km melting each day.
However, it added, the rate of loss doubled for a few days earlier this month during a major storm.
Responding to the latest update, Prof Seymour Laxon, professor of climate physics at University College London, said that he was not surprised that 2012 was set to deliver a record minimum.