2010-12-11 NASA GISS
This is the warmest January-November in the GISS analysis, which covers 131 years. However, it is only a few hundredths of a degree warmer than 2005, so it is possible that the final GISS results for the full year will find 2010 and 2005 to have the same temperature within the margin of error.
As described in a paper just published in Reviews of Geophysics (see summary PDF) that defines the GISS analysis method, we estimate a two-standard-deviation uncertainty (95 percent confidence interval) of 0.05°C for comparison of global temperatures in nearby recent years. The magnitude of this uncertainty and the small temperature differences among different years is one reason that alternative analyses yield different rankings for the warmest years. However, results for overall global temperature change of the past century are in good agreement among the alternative analyses (by NASA/GISS, NOAA National Climate Data Center, and the joint analysis of the UK Met Office Hadley Centre and the University of East Anglia Climatic Research Unit).