The numbers are in: 2012, the year of a surreal March heat wave, a severe drought in the Corn Belt and a huge storm that caused broad devastation in the Middle Atlantic States, turns out to have been the hottest year ever recorded in the contiguous United States.

How hot was it? The temperature differences between years are usually measured in fractions of a degree, but last year’s 55.3 degree average demolished the previous record, set in 1998, by a full degree Fahrenheit.

If that does not sound sufficiently impressive, consider that 34,008 daily high records were set at weather stations across the country, compared with only 6,664 record lows, according to a count maintained by the Weather Channel meteorologist Guy Walton, using federal temperature records.

That ratio, which was roughly in balance as recently as the 1970s, has been out of whack for decades as the country has warmed, but never by as much as it was last year.