Global Temperature Trend Update: Third Warmest May in Satellite Record Might Portend Record-Setting El Niño

Every month University of Alabama in Huntsville
climatologists John Christy and Roy Spencer report the latest
global temperature trends from satellite data. Below are the newest
data updated through May 2014:

Global Temperature Report: May 2014

Global climate trend since Nov. 16, 1978: +0.14 C per decade

May temperatures (preliminary)

Global composite temp.: +0.33 C (about 0.59 degrees Fahrenheit)
above 30-year average for May.

Northern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit)
above 30-year average for May.

Southern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit)
above 30-year average for May.

Tropics: +0.17 C (about 0.31 degrees Fahrenheit) above 30-year
average for May.

The University of Alabama in Huntsville release
comments: 

May 2014 was the third warmest May in the 35-year
satellite-measured global temperature record, and the warmest May
that wasn’t during an El Niño Pacific Ocean warming event,
according to Dr. John Christy, a professor of atmospheric science
and director of the Earth System Science Center at The University
of Alabama in Huntsville. The global average
temperature for May was 0.33 C (about 0.59 degrees Fahrenheit)
warmer than seasonal norms for the month. The warmest May was in
1998, during the “El Niño of the century.” Temperatures in May 1998
were 0.56 C (about 1.0 degrees F) warmer than normal. May 2010 —
also an El Niño month — was second warmest at 0.45 C (0.81 degrees
F).

While May 2014 was not officially an El Niño month, indications
are that an El Niño is forming in the eastern central Pacific off
the equatorial coast of South America. Even if that El Niño is
nothing spectacular, it might become a record setter simply because
it is getting a warmer start, Christy said. “The long-term baseline
temperature is about three tens of a degree (C) warmer than it was
when the big El Niño of 1997-1998 began, and that event set the
one-month record with an average global temperature that was 0.66 C
(almost 1.2 degrees F) warmer than normal in April 1998.”

January through August of 1998 are all in the 14 warmest months
in the satellite record, and that El Niño started when global
temperatures were somewhat chilled; the global average temperature
in May 1997 was 0.14 C (about 0.25 degrees F) cooler than the
long-term seasonal norm for May.

“With the baseline so much warmer, this upcoming El Niño won’t
have very far to go to break that 0.66 C record,” Christy said.
“That isn’t to say it will, but even an average-sized warming event
will have a chance to get close to that level.”

Go here to see maps
showing global temperature anomalies.