PRISM3D uses multiple proxies to develop February and August synoptic reconstructions of the surface ocean. Planktonic foraminiferal assemblages were translated to February and August surface temperatures via factor analytic transfer function and the modern analog technique. Mg/Ca and alkenone paleothermometry were incorporated as supplementary data for the first time in a PRISM reconstruction. Individual time series were calibrated to age using a combination of magnetobioisostratigraphy, and warm peaks within the PRISM interval were averaged.These warm peak averages for February and August form the basic data used to produce contour maps of mid-Pliocene SST. Wherever other proxy data were available, they were plotted and interpreted [...]