Friday, January 18, 2013

Average Winter Temperatures: The Long View

Reader Gary asked about Fairbanks-land temperatures over the course of the entire winter. Now what winter means in Fairbanks is an interesting question, but obviously simplistic definitions like Solstice to Equinox (Dec 21-Mar 20) are not very helpful (How is December 15th not winter in Fairbanks but March 19th is winter?). An easy way is simply to split the year in half, a cold season (Oct-Mar) and a warm season (Apr-Sep). This roughly corresponds to the snow cover season, so is a useful "first crack".

Here's a plot of cold season mean temperatures. I've included data from the Experiment Station back to the winter of 1918-19 to highlight the correlation of temperatures on the Pacific Decadal Oscillation phases (the transitions are marked). 

Gary also asked if there was any correlation between winter temperatures and the following summer. The short answer, using just the half year seasonal means is no, none at all (correlation =0.04).


  1. Excellent Rick! As I fear, we seem to be sliding into a cooler period in Fairbanks, relative to the warm allegedly PDO-driven era from ~1976 to the the mid-2000's. The phase changes are very helpful as well.


    (maybe I should learn to golf and move south...but that's not gonna' happen)

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  3. Very interesting graph - I am somewhat surprised considering what we read everywhere nowadays. Well done!

    1. Winter climate in Alaska south of the Brooks Range is so dominated by the PDO. However, while it has cooled off, it most definitely has not returned to pre-1976 levels. That, I think, is the larger scale warming signal.