WASHINGTON - This past September was the hottest ever worldwide -- the seventh monthly record set this year.

The U.S. National Oceanic and Atmospheric Administration calculated a global temperature for September of 60.62 degrees (15.9 degrees Celsius), beating the record set in 2014.

Seven of the nine months this year have broken monthly global heat records, tying 1998 for the most monthly heat records broken. This year, only January and April did not surpass records going back to 1880.

Climate scientists blame man-made global warming and El Nino.

This is has been the hottest first nine months of any year. NOAA climate scientist Jessica Blunden said it would take a highly unlikely cold stretch the rest of the year for 2015 not to pass 2014 as the hottest on record.