July 's average high temperature exceeds 20th - century averages by more than 3 degrees . they ca n't feed and spurred the U.S. Department of Agriculture to designate more than half of all U.S. counties as disaster zones . The first seven months of 2012 are the warmest since record - keeping started in 1895 , he says . The high temperatures have contributed to a drought that has affected farmers .
July 's average high temperature exceeds 20th - century averages by more than 3 degrees . The first seven months of 2012 are the warmest since record - keeping started in 1895 , he says . The high temperatures have contributed to a drought that has affected farmers .