The 64 at MDT just after midnight sounds accurate. I remember being worried about being screwed out of a white Christmas because of how warm it got Christmas Eve and then we got a bunch of snow in Pittsburgh on Christmas Day.
So what do we have here? Christmas 2021 has a solid chance to be warmer in many parts of PA than:
Friday and Saturday of Easter weekend
Mother’s Day
2 out of the 3 days of Memorial Day weekend
Thanksgiving