Nationally, last month was the 21st coolest December in the 119-year period of record, according to the National Climate Data Center, coming in at 2 degrees below Fahrenheit.
It marked the third consecutive below-normal month, and helped drag down 2013 to 37th place on the warm list.
After a September that was the seventh-warmest on record, the composite temperature for contiguous 48 states finished at 0.7 below in October, and 0.4 in November, the Climate Center reported Wednesday.
Locally, September, October, and December -- despite snowfall that was more than triple the monthly average -- all had above-normal temperatures officially in Philadelphia.
For the year, the annual temperature at Philadelphia International Airport, 56.4, made 2013 the 23rd warmest in the 140-year dataset.
But that was a 2.4-degree drop from 2012, and coolest year since 2008.
The 55.88 inches of precipitation measured officially constituted Philadelphia's third-wettest year on record. Of note, three of the six-wettest years have occurred since 2009.
The Climate Center's global temperature report is due next week.