A scorching spring helped make last year the warmest on record in the contiguous United States, according to scientists at the National Oceanic and Atmospheric Administration (NOAA).
Spring of 2012 (March-May) was the hottest ever recorded, while the winter months were the fourth warmest ever. The average temperature for the year was 55.3 degrees Fahrenheit, one full degree warmer than the previous record hot year of 1998. The heat wave was felt all over: More than 450 cities in 46 states experienced their hottest year ever, with Des Moines, Iowa experiencing the biggest jump in temperature.
Scientists told the AP that the huge temperature increase is a combination of natural weather events like La Nina and climate change from greenhouse emissions. "A picture is emerging of a world with more extreme heat," Andrew Dessler, a Texas A&M University climate scientist told the AP. "Not every year will be hot, but when heat waves do occur, the heat will be more extreme. People need to begin to prepare for that future."
[2012 Year in Review: Superstorms, scorchers and Hurricane Sandy]
The crushing heat combined with a dry spell to create a drought that covered most of the nation. Last July, 61 percent of the country was in a drought, as 2012 was the driest year since 1988.