-40° Reached

The first measured -40° temperature of the season (as far as I'm aware) was observed in Alaska this morning, as the thermometer at Toolik Field Station registered -42 °F at 2am AKST.  A couple of sites came close to this benchmark of winter cold on November 28 (-36 °F at Arctic Village, -35 °F at Chicken).  Here's an infrared image from the Suomi-NPP satellite at 0516 AKST this morning, with the location of Toolik Lake indicated; it looks like many locations north of the Brooks Range were at least as cold.

It's late in the year to be observing the first -40° temperature, but there have been 7 years since 1950 in which it occurred even later; the 1950-2013 record latest was in 2002, when -40° was not reached until December 30.

The first -40° temperature of the season is most often observed at places such as Allakaket, Bettles, Umiat, Chandalar Lake, and Northway.  Historical data from Toolik Field Station began in 1988, and that year was the only other year in which Toolik was the first place to reach -40°.

Here's the Toolik webcam image looking south an hour before solar noon today.