That worldwide average tops the previous hottest months of July 1998 and July 2010. July is typically the hottest month of the year.
July was the hottest month ever recorded for several cities in Austria, which has been keeping records for 249 years. Spain, Germany and the United Kingdom both broke all-time July heat records, while France had its third-warmest July.
Bandar Mahshahr, Iran, set one the most extreme heat records ever measured in the world on July 31. According to media reports, the city's air temperature of 115, combined with a dew point of 90 degrees, created a heat index of 165, NOAA said.
The United States was one of the few areas that was spared of the extreme heat, along with parts of western Asia. While July was slightly warmer than average in the United States, no states set a record high, according to NOAA.
Nine of the 10 hottest months since records began have occurred since 2005, NOAA said. The agency expects 2015 will be the hottest year on record, as the first seven months of the year have already set an all-time temperature record for the period.
NOAA said the record heat reaffirms that the Earth is warming, boosted this year by an El Niño warming of the Pacific Ocean.
"The world is warming. It is continuing to warm. That is being shown time and time again in our data," said Jake Crouch, physical scientist at NOAA's National Centers for Environmental Information.
"Now that we are fairly certain that 2015 will be the warmest year on record, it is time to start looking at what are the impacts of that? What does that mean for people on the ground?"
