WASHINGTON — Something about September keeps bringing out record heat in the world.
The globe last month matched a record for the hottest September, set in 2005. It was the third time since 2000 that the world set or tied a heat record for September. In addition to 2012 and 2005, previous hot September records were set in 2003. And these records go back to 1880.
Last month’s average temperature was 60.2 degrees Fahrenheit worldwide, which is 1.2 degrees above normal, the National Oceanic and Atmospheric Administration said Monday.
Deke Arndt, NOAA climate monitoring chief, said it may be worth studying why September, more than other months, keeps setting records. It might be the lengthening of the Northern Hemisphere summer as a result of manmade global warming and continual loss of Arctic sea ice that indirectly helps cool other parts of the world, said Andrew Weaver, a University of Victoria climate scientist.
This is the 16th time that the world has set or tied a heat record since 2000, according to NOAA. The last time the world set a record for cold was in December 1916, nearly 96 years ago.
These record-setting trends are manmade global warming at work, Weaver said.
‘‘What’s playing out is precisely what climate said we should expect to see 20 to 30 years ago,’’ Weaver said.
For most of the year, world temperatures were warmer than normal, but not near record levels.