Sea surface temperature, marine air temperature, and land air temperature measured by tens of thousands of different thermometers of various types. (nap.edu)
The relative coldness of the land around 1885 to 1895 comes from the Northern Hemisphere continental interiors, particularly in winter, as global coastal land air temperature and adjacent SST anomalies agree well at this time (Parker et al., 1995), confirmed by the Jones et al. (2001) data. (ipcc.ch)
Figures 2.7 a to c show annual time - series of anomalies of combined land - surface air temperature and SST for the hemispheres and globe since 1861, based on the latest CRU land air temperature data and the UKMO SST data. (ipcc.ch)