As our Emily Babay reported on philly.com, the official Philadelphia high-temperature for Dec. 15 was toppled even before last call when it hit 69 at 1:14 a.m.
Since this was the fourth consecutive day of new high-temperature standard, that ties a record.
The city has set high-temperature records four straight days three other times in the period of record, dating to 1874 – June 4, 5, 6, and 7, 1925; Oct. 4-7, 1941, and March 12-15, 1990. Never has it happened five days in a row.
Another, probably less-noticeable record is all but certain to fall by midnight. The highest daily minimum for a Dec. 15 is 46, in 2011.
The reading at the Philadelphia International Airport measuring station is unlikely to get below 50 before midnight.
One may wonder when will this all end. A brief cool-down is coming, but the warmth won't stay away for long.
As Glenn Schwartz noted, we could well head back toward 60 for Christmas; the Dec. 25 record is 68, set in 1964.
Kenneth James at the government's Weather Prediction Center pointed out that a decent amount of snow covers areas to our north. That would tend to chill air masses from Canada that made it this far south.
And the latest Rutgers University Global Snow Lab report shows substantial snow coverage in parts of the West. In Denver, the temperature is in the teens and a winter-storm warning is in effect.
But that evidently is more symptomatic of the overall persistent pattern of lower pressure, or troughing in the West, which favors storms and cold, and its mirror opposite in the East.