Steve McIntyre over at Climate Audit has had his hard work pay off with a discovery that the USA temperature data of Dr James Hansen of NASA GISS has concealed an error in recent years. This I understand affects the ranking of which is the hottest year in USA thermometer history. NASA had claimed 1998 as the hottest year for USA but I understand that after this error is allowed for, 1934 is still the hottest year.
It is a shame that the Climate Audit site is down as I write but they will be back again pretty soon I am sure.
I thought I would just quickly illustrate that there is little agreement bewteen the big climate groups about the ranking of 1934 and 1998. Using data from the KNMI ClimateExplorer.nl
We see that the Hadley Centre and Jones both have 1998 well below 1934. Jones CRUT2 stops in 2005 but the Hadley Centre CRUT3 has 2006 (1.08689) almost as warm as 1934 (1.09514).
The GHCN based CAMS has 2006 relatively lower than the UK based groups and the Spencer and Christy satellite data from the lower troposphere sees 1999 higher than 1998 and 2006 not notably warm as the Hadley Centre finds but the satellite data obviously includes areas of ocean while all the other series are land only.