Newswise — Global climate trend since Nov. 16, 1978: +0.13 C per decade

January temperatures (preliminary)

Global composite temp.: +0.72 C (about 1.3 degrees Fahrenheit) above 20-year average for January.

Northern Hemisphere: +0.84 C (about 1.51 degrees Fahrenheit) above 20-year average for January.

Southern Hemisphere: +0.61 C (about 1.1 degrees Fahreneheit) above 20-year average for January.

December temperatures (revised):

Global Composite: +0.29 C above 20-year average

Northern Hemisphere: +0.33 C above 20-year average

Southern Hemisphere: +0.25 C above 20-year average

(All temperature anomalies are based on a 20-year average (1979-1998) for the month reported.)

Notes on data released Feb. 10, 2010:

A large El Nino Pacific Ocean warming event exposed the atmosphere to enough extra heat energy to cause the warmest January and the third warmest month overall in 32 years, and the warmest month in almost a decade (compared to seasonal norms), according to Dr. John Christy, professor of atmospheric science and director of the Earth System Science Center (ESSC) at The University of Alabama in Huntsville.

"This has the potential of breaking the records set in February and April 1998, during the 'El Nino of the Century,'" Christy said. "I looked at sea surface temperatures in the Central Pacific and it wasn't as warm as 1998, but what is there is spread out further than it was in 1998. That exposes the atmosphere to a lot of extra heat."

Hottest months in the satellite record(Compared to seasonal norms)Apr 1998 +0.76 CFeb 1998 +0.76 CJan 2010* +0.72 CMay 1998 +0.65 CJan 2007 +0.59 CJan 1998 +0.58 CJun 1998 +0.57 CMar 1998 +0.53 CJul 1998 +0.52 CAug 1998 +0.51 CNov 2009 +0.50 CJan 2005 +0.49 C

Hottest Januaries in the satellite record(Compared to seasonal norms)

2010* +0.72 C2007 +0.59 C1998 +0.58 C2005 +0.49 C2003 +0.48 C2002 +0.40 C2004 +0.37 C2006 +0.37 C2009 +0.30 C1988 +0.27 C1999 +0.17 C1987 +0.14 C

Hottest months in the tropics

Feb 1998 +1.31 CJan 1998 +1.09 CApr 1998 +1.06 CMar 1998 +1.05 CMay 1998 +0.89 CJan 2010* +0.74 CDec 1997 +0.73 CFeb 2005 +0.68 CDec 1987 +0.62 CMar 1983 +0.60 CJan 1983 +0.58 CJan 2007 +0.58 C

Hottest months, southern non-tropics

Jul 2009 +0.71 CJan 2010* +0.58 CNov 2009 +0.58 CFeb 1981 +0.55 COct 2002 +0.49 CAug 1996 +0.47 COct 2005 +0.46 CFeb 2001 +0.45 CJun 1998 +0.44 CSep 2002 +0.44 CSep 1980 +0.44 CApr 2002 +0.44 C

Hottest months, northern non-tropics

Apr 1998 +1.01 CFeb 2009 +0.99 CFeb 2006 +0.97 CFeb 2007 +0.89 CFeb 2004 +0.88 CMar 2008 +0.88 CJan 2007 +0.86 CJan 2010* +0.84 CFeb 1999 +0.84 CMar 2004 +0.84 CMar 2007 +0.83 CJul 1998 +0.82 C

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 where 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 Christy nor Spencer receives 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 federal and state grants or contracts.