A collection of geochemical SST proxy from the Last Glacial Maximum (23-19 ka) and the Late Holocene (4-0 ka) and results from data assimilation with iCESM 1.2. Includes raw proxy data from the LGM (Tierney2020_LGMProxyData.csv) and LH (Tierney2020_LHProxyData.csv) time slices, with calibrated absolute SSTs; "paired" (data in the same location) proxies with calibrated SST anomalies (Tierney2020_ProxyDataPaired.csv); a 5˚ x 5˚ gridded product of the paired proxies in netCDF format (Tierney2020_ProxyData_5x5_deltaSST.nc); and the results from the DA in netCDF format. The DA results are split into atmospheric variables (SAT, d18O of precipitation; Tierney2020_DA_atm.nc) and oceanic variables (SST, SSS, and d18O of seawater; Tierney2020_DA_ocn.nc). The ocean data are provided on their native tripolar grid (Tierney2020_DA_ocn.nc) as well as a 1 x 1 regridded version (Tierney2020_DA_ocn_regrid.nc).