Twice As Warm?

With the significant temperature differences between March, 2012 and what has been recorded this March, comparisons are inevitable.  One statement I have read several times was to compare last year to this year by stating “last March was more than twice as warm as this year”.  A year ago, Fargo Moorhead recorded several days in the 60s and 70s, this year, mainly 20s, so just looking at the numbers, you would think such a statement would be factually correct, yet, it is not.

Surface temperature readings in the United States are given in degrees Fahrenheit.  If we used the Celsius scale last March temperatures would have been in the 20s and this year in the -0s, obviously not “twice as warm”.  Temperature scales use arbitrary numbers to represent the measurement of the amount of heat present.

Therefore, representing temperature differences in fractional terminology is not correct unless your starting point is absolute zero and you state the scale you are using