A good year for shorts

Last year was, by a wide margin, the hottest ever recorded in the contiguous United States.

While year-to-year temperature differences are typically measured in fractions of a degree, 2012’s average temperature (55.3 degrees) was a whole degree higher than the previous record set in 1998, according to The New York Times. More than 34,000 daily-high records were recorded at weather stations across the country, compared to 6,664 record lows.

Experts maintain natural variability almost certainly played a role in the record-setting year, but also suggest such extremes would not have been reached without greenhouse-gas emissions from human activity. Many have warned 2012 is also a taste of things to come, as climate change makes weather extremes more common.

Last year was marked by an extreme March heat wave, widespread drought in the Corn Belt and super-storm Sandy in the Middle Atlantic states.

“The heat was remarkable,” said Jake Crouch of the National Climatic Data Center in Asheville, N.C. “It was prolonged. That we beat the record by one degree is quite a big deal.”