Federal officials say July was Earth's hottest month on record, smashing old marks.
July's average temperature was 61.86 degrees Fahrenheit, beating the previous global mark set in 1998 and 2010 by about one-seventh of a degree. That's a large margin for weather records.
Records go back to 1880, but nine of the 10 hottest months on record have happened since 2005.
The first seven months of 2015 are the hottest January-to . . .
