2015 saw things heat up and get out of hand, and not just in politics.
A record warm December raised average temperatures enough to make 2015 the second hottest year on record in the contiguous United States, according to the National Oceanic and Atmospheric Administration's National Climate Monitoring Annual Report, which was released Thursday.
The United Nations had previously reported that 2015 was shaping up to be the warmest year on record for the whole planet.
Last year was also the third wettest on record in the U.S. and saw ten weather- or climate-related disasters that each caused at least $1 billion in damage in the U.S. and killed a total of 155 people. These include a drought, two floods, five severe storms, a wildfire, and a winter storm.
The average U.S. temperature was 54.4°F, 2.4°F above the 20th century average, and second only to 2012's record warmth. This was also the 19th consecutive year with average temperatures above the average for the century.
Every state reported above-average annual temperatures. The warming was particularly pronounced across most of the eastern half of the country in December, when many places saw temperatures 30 degrees above normal and many records were set.
This mirrored changes seen in the Arctic that month, when temperatures spiked to 50 degrees above normal. Part of this warming was driven by a strong El Niño, or periodic warming in the Pacific Ocean, but some of it can also be attributed to global warming, says meteorologist Eric Holthaus, who was not involved with the federal report.
The analysis comes less than a month after the U.S. and 194 other countries signed an agreement in Paris to more aggressively counter the effects of climate change.
A supercell thunderstorm strikes in South Dakota. Among the most severe storms, supercells can bring strong winds, hail, and even tornadoes. (See more extreme weather pictures.)
“Even if all the initial targets in Paris are met, we’ll only be part of the way there when it comes to reducing carbon from the atmosphere,” said President Barack Obama at the time. Still, the agreement represented “a turning point” by setting up “the architecture" for doing so, he said.
NOAA's climate monitoring center doesn't issue predictions for future weather, but the agency's Climate Prediction Center does. That team's forecast for the next three months calls for warmer-than-average temperatures in much of the country, although parts of Texas and the Southeast may be a little cooler than usual.
As Lancaster University Professor Gail Whiteman told the Weather Channel, "climate change means extreme weather is the new normal."