The National Oceanographic and Atmospheric Administration reports that July capped the warmest 12-month period the United States has experienced since weather record keeping began in 1895.
The average of 77.6 degrees Fahrenheit topped the previous warmest July, which was in 1936 when the average U.S. temperature was 77.4 degrees.
U.S. Rep. Ed Markey, D-Mass., ranking member of the House Natural Resources Committee, called on his Republican counterparts to support extending an expiring tax credit that supports renewable energy resources like wind energy.
"(Republicans) are too busy carrying water for big oil companies who are pocketing billions in taxpayer subsidies at the expense of clean energy like wind," he said in a statement.
A report to be published in the Proceedings of the National Academy of Sciences from National Aeronautics and Space Administration scientists said extreme weather events like this year's heat wave can't be explained by natural phenomena alone.