When It's Winter in Alaska
When this article was originally released, it was accompanied by a different local weather chart for each location to which it was sent. Today similar charts are available for a number of Alaskan locations on the Internet.
Five months ago, this column was devoted to a summary of the average climates around Alaska during the "warm" season -- April through September. We're now well into the cold season, and it's time to look at the weather around the state in the interesting part of the year. The variability from place to place and even from day to day is extreme.
The Interior once again has the most spectacular record, with differences between record high and record low temperatures in December and January being as much as a hundred and ten degrees F -- from 50 above to 60 or even 70 below. Changes can be fast, too -- during January of 1934 in Fairbanks, the temperature on the 6th was 35 above. By a week later, on the 14th, it was 66 below, and on the 26th, 60 below. But by the 29th, it had soared again -- to 33 above!
Record low temperatures on the Arctic Coast are actually warmer than those in the Interior, though the averages are lower and the relatively high winds make things feel colder. Also, there is enough solar heating to begin warming up the Interior by February. At Barrow, the sun doesn't even rise until January 20, and February is the coldest month there. Both the North Slope and the Interior are dry, with precipitation measured in hundredths of an inch per day.
Southeastern and the Aleutians provide a striking contrast to the Interior and North Slope. In the Aleutians and the southern parts of southeastern, normal daily temperatures fluctuate through the freezing point at the coldest time of the year. Even at Juneau, where the average daily high is in the 20s, thawing temperatures are common. Southeastern in particular is at its wettest in October, with the precipitation declining through the winter to between half and a third of the October value by March. Record low temperatures range from zero to 20 below. Since the October precipitation averages a quarter of an inch to an inch per day, the warmth is paid for with wetness. The Aleutians, with the smallest range of temperatures in the state, simply stay wet through their warm winters, where temperatures almost never fall as low as zero.
The Bering Sea Coast is neither as cold as the Interior (though 40 below temperatures are not unknown) nor as dry, but over all it resembles the Interior more than it does Southeastern.
The Southcentral area outside of Cook Inlet is perhaps best described as combining the temperatures of Homer with the precipitation of Southeastern - a combination that is responsible for the spectacular glaciers of the region.
Cook Inlet has some surprises, probably related to the exact location of the weather stations relative to the coast. Anchorage, for instance, has official January record low temperatures around 30 below, while Kenai's are closer to 40 below. Precipitation is about twice that of the Interior. The relative warmth and higher precipitation of Homer, which rarely reaches even 20 below, is explained by its greater exposure to the waters of the relatively warm Gulf of Alaska.
In general, parts of the state well away from the oceans have cold winters with a lot of variability but not much precipitation, while those adjacent to open water are much warmer, more uniform in temperature, and wetter -- all related, as are the summer temperatures, to the ability of water to store heat. The presence of an ice-covered ocean in the neighborhood has effects on temperature somewhere between those of open water and of dry land.
If there is any doubt remaining about the importance of warm oceans, consider Tromsø, in Norway. Located at almost the same latitude as Barrow but adjacent to the warm waters of the Gulf Stream, its winter climate is warmer than Juneau's!
