Global Temperature Report – May 2008

May headlines:
Tropics see 5th coolest month;
Globe coolest since Jan. 2000
Global trend since Nov. 16, 1978: +0.13 C per decade
May temperatures (preliminary)
Global composite temp.: – 0.18 C (about 0.32 degrees Fahrenheit) below
20-year average for May.
Northern Hemisphere: – 0.05 C (about 0.09 degrees Fahrenheit) below 20-year
average for May.
Southern Hemisphere: – 0.31 C (about 0.56 degrees Fahrenheit) below 20-year
average for May.
April temperatures (revised):
Global Composite: + 0.02 C above 20-year average
Northern Hemisphere: + 0.17 C above 20-year average
Southern Hemisphere: – 0.14 C below 20-year average
(All temperature variations are based on a 20-year average (1979-1998) for
the month reported.)
Notes on data released June 4, 2008:
Global average temperatures and temperatures in the tropics continued to
fall in May, driven by a La Nina Pacific Ocean cooling event.
Compared to seasonal norms, temperatures in the tropical third of the globe
nearly tied for the fourth coolest month in 29 years, while the globe was
cooler than at any time since January 2000, according to Dr. John Christy,
director of the Earth System Science Center at The University of Alabama in
Huntsville.
A broad band of cooler than normal air virtually girdled the globe in May.
The tropics were 0.58 C (about 1.04 degrees Fahrenheit) cooler than seasonal
norms in May.
Coolest months in the tropics:
March 1989 – 0.73 C (-1.31 F)
February 1989 – 0.63 C (-1.13 F)
December 1988 – 0.62 C (-1.12 F)
July 1985 – 0.583 C (-1.05 F)
May 2008 – 0.579 C (-1.04 F)
As part of an ongoing joint project between UAHuntsville, NOAA and NASA, Christy and Dr. Roy Spencer, a principal research scientist in the ESSC, use data gathered by microwave sounding units on NOAA and NASA satellites to get
accurate temperature readings for almost all regions of the Earth. This
includes remote desert, ocean and rain forest areas for which reliable
climate data are not otherwise available.
The satellite-based instruments measure the temperature of the atmosphere
from the surface up to an altitude of about eight kilometers above sea
level.
Once the monthly temperature data is collected and processed, it is placed
in a “public” computer file for immediate access by atmospheric scientists in the U.S. and abroad.
Neither Spencer nor Christy receive any research support or funding from
oil, coal or industrial companies or organizations, or from any private or
special interest groups. All of their climate research funding comes from
state and federal grants or contracts.
Dr. John Christy, UAH, (256) 961-7763
john.christy@nsstc.uah.edu
Dr. Roy Spencer, UAH, (256) 961-7960
roy.spencer@nsstc.uah.edu