July was the second hottest month, averaging 77.2 degrees in the 48 contiguous states of United States, just below the record of 77.5 set in 1936.
The National Climatic Data Center says the normal average for the month is 74.3 degrees.
This summer's heat wave has already killed more than 200 people, USA Today reported.
July's near-record average is consistent with scientists' models of global warming, said Jay Lawrimore, who runs the data center's Climate Monitoring Bureau, the newspaper reported. He said the models suggest the warming will trigger more heat waves.
"The bottom line is we expect this to occur more frequently in the future, so I think people need to get used to it," Lawrimore said.
Copyright 2006 by United Press International
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