The Arctic Ocean sea ice reached its maximum extent in mid to late March of this year. The only time in the last five years when the sea ice extent was this large this late in the spring was in 2010 when it reached it's maximum in at the very end of March/very beginning of April.
Graph courtesy of the National Snow and Ice Data Center at the University of Colorado at Boulder. (NSIDC).
The reason the sea ice extent is so large this year is that we have had colder than average conditions in the North Pacific. The white area on the map below shows the extent of sea ice cover (at least 15% cover) as of 5/21/2012. The orange lines show the 1979-2000 average extent of sea ice.
Take a look at the Bering Sea, west of Alaska and north of the Aleutian Islands. There's a LOT more ice there than usual. The same thing is true for areas west of the the Kamchatka peninsula by coastal Russia and north of Japan. In the north Atlantic, however, the melt is near normal by eastern Canada and Greenland. It's ahead of normal, though, north of Scandinavia and northwest of the Kara Sea.
I can't imagine that the ice in the north Pacific is going to last that much longer, but we'll just have to wait and see.
The take-home message? The melt is underway, and though it's been slower than usual for May, it's still melting faster than average over all.