HadCRUT

http://www.cru.uea.ac.uk/cru/data/temperature/

CRUTEM4

http://www.metoffice.gov.uk/hadobs/crutem4/data/download.html http://www.cru.uea.ac.uk/cru/data/temperature/crutem4/station-data.htm

http://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/tree-ring

http://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/climate-reconstruction

http://en.wikipedia.org/wiki/Temperature_record