The continental United States experienced its hottest year on record in 2012, according to the National Climatic Data Center.
The average temperature for 2012 was 55.32 degrees Fahrenheit (13 degrees Celsius), smashing the previous record by a full degree.
That's unprecedented, scientists say. Most record years best the previous record by only about a tenth of a degree.
July 2012 was also the hottest single month since records began being kept back in 1895, according to the National Oceanic and Atmospheric Administration (NOAA), the nation's premiere weather prediction agency.
The drought that hit the Midwest this past summer was the worst since the 1950s, and it fell just short of beating out the Dust Bowl of the 1930s. This year's drought destroyed crops and killed herds.
Only 1998 had more extreme weather events, and this year's Hurricane Sandy, the drought and other disasters caused more than $1 billion in damages.
The findings are sure to reignite debate about climate change and global warming. The vast majority of climate scientists believe that human actions have contributed significantly to climate change, particularly the massive amounts of carbon and greenhouse gases that have been released into the atmosphere since the dawn of the Industrial Revolution.
"It is abundantly clear that we are seeing climate change in action," said Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research in Boulder, Colo., who did not participate in the NOAA report.
"These records do not occur like this in an unchanging climate," he said. "And they are costing many billions of dollars."
While the United Nations reauthorized the Kyoto Protocol at a climate summit in Doha, Qatar, last year, the international plan meant to curb emissions of greenhouse gases has largely been a failure. The United States never signed onto the treaty, and recently Canada, Australia, and Japan all dropped their support.
Developing countries, like India and China -- the latter is now the world's largest polluter, followed by the United States -- were never bound by the treaty, which sought to limit emissions to 1990 levels. Worldwide emissions are now 50 percent higher than they were in 1990 and continue to climb.
Temperature data for the rest of the world will be released next week, but it is likely that 2012 will break many records across the rest of the planet, too.
"A picture is emerging of a world with more extreme heat," said Andrew Dessler, a Texas A&M University climate scientist. "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."