In the period of record, which the U.S. government dates to 1880, the annually averaged global temperature never has changed month-to-month more than a degree Fahrenheit in either direction.
So the only thing that would keep 2015 from becoming the warmest on record in the National Climatic Data Center – surpassing last year -- would be a December cool-down beyond precedent.
And that's not going to happen.
From Jan. 1 through Nov. 30, the combined land-and-sea temperature was 1.57 degrees above 20th Century averages, the climatic center reports. Yes, that's a record.
The margin of error was plus or minus 0.16.
The December reading would have to be 1.46 degrees below the 20th Century average, or better than three whole degrees colder than November's.
And with the El Niño cooking in the tropical Pacific, chances are that if anything, December could set a record high for the month.
And, yes, this was the warmest November in the database, and the warmest fall.
And, yes, locally, December is all but sure to be Philadelphia's warmest final month of the year.