Strong southwest flow continued across the Gulf of Alaska and the southern mainland of Alaska for the first 11 days of December. In this environment, a series of vigorous North Pacific low pressure systems moved across the Aleutians into the Bering Sea. Persistent westerly wind aloft was established over the Aleutians on December 16. This changed the destination of North Pacific storms to the Alaska Peninsula and the Gulf of Alaska.

Temperatures were above normal nearly everywhere in Alaska, especially in the Interior, where an inflow of warm air from the Pacific persisted for the first three weeks of December. Had this influx of warm air continued through the end of December, a number of locations would have had their warmest Novembers in up to 100 years.

The moisture in this influx of maritime air was the source of the above normal precipitation in nearly all of Alaska. In the first three weeks of December, calendar day records for high temperatures and heavy precipitation were set at some weather stations in the Interior, western Alaska and the southern mainland.

On December 22, cold low pressure aloft began to settle over the Alaska mainland, and temperatures began falling nearly everywhere in Alaska. During the last eight days of December, calendar day low temperature records were set at three stations on the Alaska Peninsula and Kodiak Island. Thus, the warm December temperatures were a mirror image of the cold temperatures of November.

Gale force winds swept over portions of Alaskan ocean waters for the first 28 days of December. Several large cargo ships took refuge in bays in the Aleutians during the first 10 days of December. Marine weather during the last three days of December was relatively quiet.

The strongest storm of November crossed the central Aleutians on the evening of December 2 enroute to the Bering Sea, where it reached a strength of 960 millibars (28.35 inches) on December 3. After moving north over Bering Strait on December 4,  most of the storm's energy was transferred to the southeast Beaufort Sea. This weather system was strong, long-lived and covered a remarkably large area. On December 7, it reached the central Arctic coast of Canada, and continued moving eastward.

This storm, and several which followed it, brought periodic blizzards to much of the mainland of Alaska. There was freezing rain in parts of the southern Interior on December 11. Major wind storms on the Kenai Peninsula and around Anchorage caused electric power outages to several thousand customers on December 11, 17 and 18. Very much as it was in December, 2010, the village of Savoonga was without electric power for three days due to ice accumulation from freezing spray blown ashore by storms.

The pending fuel shortage at Nome spurred resourceful leaders of the local Native corporation to charter the Renda, a double-hulled, 371 foot Russian tanker certified to make way through ice up to four feet thick. The Renda arrived in Dutch Harbor on January 2. The Coast Guard ship Healy, the sole American polar class icebreaker in active service, was diverted from a mission of scientific research in the Bering Sea to break way through the ice and escort the Renda to Nome in January.

The availability of these unique ships was a remarkable instance of good fortune, as the winter ice in the Bering Sea was rapidly expanding. At the end of December, the edge of the ice extended from 50 miles seaward from the coast of northern Bristol Bay to 150 miles south of Saint Lawrence Island. Most of the ice was from two to four feet thick.

Warmer than normal temperatures during the first three weeks of December caused the ice in Cook Inlet to retreat significantly. On December 15, there was no ice on the east shore below the East Foreland and only small stretches of new and thin ice along shore south of Kalgin Island. As temperatures turned sharply colder during the last eight days of December, the ice resumed growth above the Forelands and along the west shore.

At the end of December, the extent of ice cover was a little more than normal in both Cook Inlet and the Bering Sea. Sea surface temperatures in Alaskan waters remained from 2°F to 5°F cooler than normal, except along the Alaska Peninsula, surface water temperatures were near the normal values of December.

Gradual subsidence of the lava dome on the Mount Cleveland volcano in the eastern Aleutians continued during December. However, a single and minor explosive eruption early on December 29 sent an ash plume up as high as 15,000 feet. The plume moved southeastward, out to sea, and caused no problems. There were no significant earthquakes.

The cold weather of November, counterbalanced by the warmth in December, resulted in close to normal ice thickness – mostly around 20 inches – on mainland  lakes and rivers at the end of December. On December 30, an ice jam formed on the lower Kenai River, which drains into the east shore of Cook Inlet. Fortunately, the ice jam released slowly, thus averting flooding.