(Justin Grieser, data from NWS)
(Justin Grieser, data from NWS)

Post-Thanksgiving Update: The high temperature at Reagan National reached 40 degrees on Thanksgiving, bumping 2013 down to 16th-coldest Thanksgiving by high temperature. Yet the average temperature of 34 degrees still made it the coldest Turkey Day since 2002 and the 4th-coldest since 1980.

Original post (from 11/27):

In the wake of an East Coast storm creating a travel headache before the holiday weekend, Thanksgiving Day in the nation’s capital will be cold and blustery this year. If high temperatures stay in the mid-30s (well below our average high of 53 degrees), it would place 2013 among D.C.’s ten coldest Thanksgivings since 1871.

(Justin Grieser, data from NWS) (Justin Grieser, data from NWS)

Taking into account the variable dates of Thanksgiving, this will be the coldest Turkey Day since 2000 (and perhaps colder), when the high only reached 38 degrees on Nov. 23. This year’s late Thanksgiving will be much like 1996, when Thanksgiving also fell on Nov. 28. That year the high temperature was 35°F and the low was 26°F, making it D.C.’s fourth-coldest Thanksgiving on record.

Thanksgiving 2013 will be the third day this month on which temperatures fail to reach 40 degrees. As CWG’s Ian Livingston wrote last week, the last time D.C. had three or more sub-40-degree days in November was in 1956.

How often can D.C. expect daytime temperatures in the 30s on Turkey Day? Generally, about 10 percent of the time, compared with a 53 percent chance of highs in the 40s or 50s and a 31 percent chance of highs in the 60s. The chart below shows temperatures in the 60s have become more common in recent decades. Yet wintry 30s are still more likely than a warm Thanksgiving in the 70s, which occurred in only 2 of the last 32 years. In 2007 the temperature at Reagan National Airport hit a record 77 degrees on Nov. 22, marking D.C.’s warmest Thanksgiving on record.

Frequency of high temperatures recorded on Thanksgiving in Washington, D.C. from 1872-2012. (Justin Grieser)

While 2013 will be among D.C.’s coldest Thanksgivings, daily low temperatures will be short of record-breaking. That distinction belongs to 1903, when the low dropped to 19 degrees on November 26. At Reagan National, the coldest Thanksgiving morning was 25 degrees on November 24, 2005.  This Thanksgiving may come close to that, with projected lows 24-28.

A White Thanksgiving?

This week’s pre-Thanksgiving storm may bring a period of wet non-accumulating snow to the region this afternoon, but those traveling in the metro area on Thanksgiving morning should catch a break from wintry precipitation. The last time Washington had measurable snow on Thanksgiving Day was in 1989. That year, 1.6″ of snow fell at National Airport the Wednesday before Thanksgiving, followed by another 1.9″ on the holiday itself.

The White Thanksgiving of 1989 was also the last time downtown D.C. had measurable snowfall at any time during the month of November. (Dulles Airport, however, last had measurable snowfall in November when 0.3″ fell the day before Thanksgiving in 2005).

Even if D.C. fails to break its November snow drought (there is a low chance opportunity this afternoon), temperatures over the holiday weekend will be unmistakably wintry.

Bundle up – and remember that indoor heat and warm clothes are something to be thankful for.

Related: DC’s Thanksgiving Day Weather History