According to the National Oceanic and Atmospheric Administration (NOAA), 2012 had an average temperature of 55.3°F, which eclipsed 1998, the previous record holder, by 1°F. That was just off Climate Central’s calculation in mid-December, which projected an expected value of 55.34°F, based on historical data.
The year consisted of the fourth-warmest winter, the warmest spring, second-warmest summer, and a warmer-than-average fall. With an average temperature that was 3.6°F above average, July became the hottest month ever recorded in the contiguous U.S. The average springtime temperature in the lower 48 was so far above the 1901-2000 average — 5.2°F, to be exact — that the country set a record for the largest temperature departure for any season on record.
During the summer, nearly 100 million people experienced 10 or more days with temperatures greater than 100°F, which is about one-third of the nation’s population, NOAA reported.