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 November, 2010.
Third warmest November leaves 2010 behind '98
Global climate trend since Nov. 16, 1978: +0.14 C per decade
November temperatures (preliminary)
Global composite temp.: +0.38 C (about 0.69 degrees Fahrenheit) above 20-year average for November.
Northern Hemisphere: +0.51 C (about 0.92 degrees Fahrenheit) above 20-year average for November.
Southern Hemisphere: +0.25 C (about 0.45 degrees Fahrenheit) above 20-year average for November.
Tropics: -0.07 C (about 0.23 degrees Fahrenheit) below 20-year average for November. October temperatures (revised):
Global Composite: +0.43 C above 20-year average
Northern Hemisphere: +0.37 C above 20-year average
Southern Hemisphere: +0.48 C above 20-year average
Tropics: +0.16 C above 20-year average
(All temperature anomalies are based on a 20-year average (1979-1998) for the month reported.)
The satellite temperature data set is available here.
Notes on data released Dec. 6, 2010:
November 2010 came in as the third warmest November in the 32-year satellite temperature record, but still warmer than November 1998, according to Dr. John Christy, professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. From January through November, that leaves 2010 only 0.012 C (0.022° F) cooler than 1998, which was the warmest year in the satellite record.
"The globe was cooling in late November, with daily anomalies around +0.1 C," said Christy. "It looks like 1998 might stay the warmest year in the record, but will most certainly be within 0.1 C—an amount that isn't significant in terms of measurement precision. It would be a statistical tie."
2010 will be the 13th consecutive year with global average temperatures that were warmer than their seasonal baseline norms.
November temperatures in the tropics were more than 0.8 C (about 1.4 degrees Fahrenheit) cooler than the +0.79 C peak in February 2010.
Technical Note:
Beginning with the December 2010 Global Temperature Report, the baseline period used to determine seasonal norms will change. It has been the 20-year (1979 to 1998) period at the beginning of the satellite record. Starting next month the report will use a new 30-year (1981 to 2010) reference average to match the climatological period normally used with climate data by the U.N.'s World Meteorological Organization.
This will not affect the long-term trend, but will "reshuffle" the anomalies to reflect the new base period.
