Most Recent 12 Month Period the Warmest in History of U.S. Recordkeeping

National Oceanic and Atmospheric Administration

State of the Climate: National Overview June 2012

Extreme heat in the second half of June helped make the first six months of this year the hottest January to June ever recorded in the lower 48 United States, according to the National Oceanic and Atmospheric Administration. Eighty-six locations set temperature records in June, with another 87 tying existing marks. That helped push the average temperature in the contiguous United States to 71.2 degrees Fahrenheit, 2 degrees above the 20th-century average. The sizzling heat capped the warmest 12 months since record-keeping began in 1895, NOAA said, inching out the previous record-holder—June 2011 to May 2012—by just 0.05 degree Fahrenheit.

In addition to the warmer temperatures, drought conditions now cover 56 percent of the contiguous United States, the highest percentage since the government-supported Drought Monitor began 12 years ago, NOAA said, helped by below-average precipitation in the West, Plains, Ohio Valley and mid-Atlantic states. Wyoming recorded its driest June ever last month. Colorado and Utah recorded their second-driest Junes, with eight other states experiencing conditions that rank among the 10th driest for the month. Precipitation totals across the country were mixed during June. The nation as a whole experienced its tenth driest June on record, with a nationally-averaged precipitation total of 2.27 inches, 0.62 inch below average.