“September’s high temperature was …. the greatest rise above average for any month in the 136-year historical record [comprised of 1,629 months],” NOAA said.
September is the fifth straight month of 2015 to set a record high. Seven of nine months this year have ranked as top warmest. The only two months to fall short were January and April, which ranked second and third-warmest.
Year-to-date, 2015 stands alone as the warmest on record by the sizable margin of 0.21 degrees (0.12 Celsius).
In August, NOAA said 2015 was so far ahead of 2014, in terms of year-to-date warmth, that there was a 97 percent chance it (2015) would surpass it (2014) as the warmest year in recorded history.
“It appears extremely unlikely that 2015 will lose its commanding lead,” NOAA said.
The record challenging El Niño event, characterized by the pronounced warming of the central and eastern equatorial Pacific Ocean, has proven a key driver of this year’s warmth.
NOAA said the El Niño, which transfers vast quantities of ocean heat into the atmosphere, may end up ranking as the second strongest on record, only trailing the behemoth event of 1997-1998.
But even as the 1997-1998 El Niño will probably turn out to be stronger than this year’s version, global temperatures have since pressed higher, pushed by unrelenting emissions of heat-trapping greenhouse gases from human activities.
The International Research Institute for Climate Prediction says new computer simulations indicate at least a 98 percent chance that El Niño conditions will persist into the early spring of 2016, which should sustain global temperatures in record territory.
“There’s no longer a possibility that El Niño wimps out at this point,” Bill Patzert, a NASA climatologist told the LA Times. “It’s too big to fail.”
During September, the global average temperature was 1.62 degrees above average. Record and near-record warmth covered sections of several continents.
“Record warmth was observed across northeastern Africa stretching into the Middle East, part of southeastern Asia, most of the northern half of South America, and parts of central and eastern North America,” NOAA said.
A global temperature analysis from the Japanese Meteorological Agency also concluded September ranked warmest on record, and by a substantial margin (0.27 degrees). NASA’s global temperature analysis indicated it was the second warmest on record, trailing only 2014.