According to an NBC report, the average temperature for 2012 was 55.3 degrees Farenheit, 3.2 degrees above normal and a full degree higher than the previous warmest year recorded -- 1998 -- NOAA said in its report Tuesday. All 48 states had above-average annual temperatures last year, including 19 that broke annual records.
The unprecedented warm weather wasn't contained to the United States.
A corresponding rise in global temperatures prompted the World Meteorological Organization to call the rate at which the Arctic sea ice was melting "alarming" in its Nov. 28, 2012, report.
Each year since 2001 has been among the warmest on record worldwide, with 2012 likely to "be no exception despite the cooling influence of La Nia early in the year," the report added.
NOAA expects to have global data for 2012 sometime in the coming weeks, but Crouch said scientists already know with certainty "it's going to be in the top ten" warmest years ever.