Permafrost borehole temperatures were measured in 1985, 1998, and 2004 on Barter Island near the village of Kaktovik and in the Arctic National Wildlife Refuge (Arctic NWR) north of the Brooks Range. These measurements indicate that the century-long warming documented for the central and western Arctic has also occurred in the region near Barter Island and in the northern Arctic NWR. At Kaktovik, the warming occurred during the second quarter of the 20th century or earlier and its magnitude exceeded 0.8°C. A more recent warming (since the mid to late 1980s) similar to that in the central and western Arctic is also occurring on Barter Island and in the northern Arctic NWR. Near Kaktovik, the permafrost warmed about 2 to 3°C from 1985 to 2004. In the northern Arctic NWR, on a line extending southward from Tapkaurak Point, it warmed about 1.5 to 2°C from 1985 to 1998. If air temperatures warm 5°C over the next century, as predicted, some of the permafrost in the northern Arctic NWR would be expected to thaw. Copyright © 2005 John Wiley & Sons, Ltd.