( CNN ) -- The past year saw a mild winter give way to a balmier-than-normal spring , followed by a sweltering summer and high temperatures that lingered into the fall , all punctuated by extreme drought and intense storms . Now 2012 is officially in the books as the hottest year on record for the continental United States and the second-worst for `` extreme '' weather such as hurricanes , droughts or floods , the U.S. government announced Tuesday . The year 's average temperature of 55.3 degrees Fahrenheit across the Lower 48 was more than 3.2 degrees warmer than the average for the 20th century , the National Oceanographic and Atmospheric Administration reported . That topped the previous record , set in 1998 , by a full degree . Every state in the contiguous United States saw above-average temperatures in 2012 , with 19 of them setting annual records of their own , NOAA said . Meanwhile , the country faced 11 weather disasters that topped $ 1 billion in losses each , including a lingering drought that covered 61 % of the country at one point . That drought shriveled crops across the American farm belt , leading to an expected rise in food prices in 2013 , according to the U.S. Agriculture Department . It also turned forests of the mountain West into stands of tinder that exploded into catastrophic wildfires over the summer , scorching millions of acres and destroying hundreds of homes . Climate change , extreme weather linked . And then there was Superstorm Sandy , a late October post-tropical cyclone that killed more than 110 people in the United States and nearly 70 more in the Caribbean and Canada . Damage estimates from the storm run around $ 80 billion in New York and New Jersey alone . The report is likely to fuel new concerns over a warming climate . Seven of the 10 hottest years in U.S. records , which date back to 1895 , and four of the hottest five have now occurred since 1990 , according to NOAA figures . The year also saw Arctic sea ice hit a record low in more than 30 years of satellite observations and studies that found the world 's major ice sheets have been shrinking at an increasing rate . Scientists are quick to point out that no single storm can be blamed on climate change , but say a warming world raises the odds of extreme weather . `` I think unfortunately , 2012 really may well be the new normal , '' said Daniel Lashof , director of the climate and clean air program at the Natural Resources Defense Council , a U.S. environmental group . `` It 's the kind of year we expect , given the global warming trend is ongoing . '' The science of global warming is politically controversial but generally accepted as fact by most researchers , who point to heat-trapping carbon emissions from the burning of fossil fuels as the major cause . Lashof 's group is trying to press the Obama administration to tighten limits on carbon emissions , but he said those steps `` are not going to reduce the threat of extreme weather overnight . '' `` We need to take greater preparations , anticipating the kind of storms and droughts that we saw are going to continue to be more frequent as we go forward , '' he said . Wildfires race across Australia . Though parts of the country such as the Pacific Northwest and the Gulf Coast had wetter-than-average years , average precipitation was nearly 2.6 inches below normal -- the 15th driest since records started being kept in the 1890s , according to NOAA . The two remaining U.S. states , remote Alaska and Hawaii , saw a mixed picture in 2012 . Alaska was slightly cooler and wetter than normal , while nearly two-thirds of Hawaii 's island chain faced moderate to exceptional drought conditions by December , NOAA said . Science , satellites and superstorms : Preparing for the next big one .
NEW : Last year 's extreme temperatures will be ` ` the new normal , '' environmentalist says . NOAA called it the hottest on record . Every state in the Lower South saw above - average temperatures ; 19 set their own records . Droughts , tropical storms and other disasters made it the second - most extreme year .