 Gridded station-based datasets for temperature, precipitation and other variables have been developed (e.g., Harris et al. 2014). Surface temperature datasets have attracted particular attention, because of their role in efforts to quantify the extent of recent global warming. Three prominent sources for such temperature datasets are NASA’s Goddard Institute for Space Studies (GISS), the University of East Anglia’s Climatic Research Unit (CRU) and the U.S. National Centers for Environmental Information (NCEI). Periodically, these groups develop new versions of their datasets reflecting both the acquisition of additional data as well as methodological innovation, e.g., addressing additional sources of inhomogeneity (see Hansen et al. 2010; Jones et al. 2012; Lawrimore et al. 2011). Despite the many different methodological choices involved in producing these datasets, there is good agreement among analyses of twentieth century global land surface temperature changes derived from them, especially for the second half of the twentieth century. Nevertheless, climate contrarians have expressed concern that these analyses exaggerate late twentieth-century warming. This recently motivated a fourth, independent analysis by the non-governmental organization Berkeley Earth; drawing on a much larger set of station records and using a quite different geostatistical methodology for handling inhomogeneities, their analysis confirmed the twentieth century global warming seen in other datasets (Rohde et al. 2013).