December 2009 may be one for the record books (top 10 coldest) given the big “head start” of cold during the first 10 days of the month.
The expected pattern through the 20th will feature fronts moving down with cold Canadian air behind each one. While brief warm-ups can be expected in between each front, a fairly extensive snowpack from Kansas to Canada will help the southward moving chills to maintain more of their coldness than they would otherwise.
Since detailed climate information for Texoma is hard to come by, we’ll use Dallas and Oklahoma City averaged together. The first ten days of December averaged together shows us to be 9 1/2 degrees below the 30-year average for the early part of the month.
For Dallas, the average temperature for Dec 1-10 was 38.9. This is 9 degrees below average and makes 2009 the 2nd coldest through this point in the month (1983 was much colder with an average of 34.8 degrees).
For Oklahoma City, the average temperature for Dec 1-10 was a chilly 31.8 degrees; this makes it the 6th coldest at 10 degrees below average.
National Weather Service graphics and data used on both tables
Combining these two, we're running about 4th coldest on record for December in Texoma. The average temperature in Texoma so far has been just above 36 degrees. Brrr!
Of course, there’s lots of month left but December 2009 may be in the top 10 coldest given the “cushion” already built up, and an overall cool pattern expected.