Daily 1/8¿ global fields of sea surface temperature (SST), operationally produced by the Modular Ocean Data Assimilation System (MODAS), are presented. Production using a combination of optimal interpolation and climatologically corrected persistence balances eddy-resolving spatial and daily temporal resolution with improved transitions in time and space across cloud-obscured regions to eliminate data voids. Hindcast reanalysis has consistently extended complete MODAS SST coverage from 1993 to the present. In validation analysis using 219 yearlong daily SST time series from both coastal and open ocean buoys over the global ocean, MODAS gives a median root mean squared SST difference of 0.41¿C. Whether hindcast or real-time, stand-alone or coupled, MODAS SST is applicable for physical or biological studies and operational applications on regional to global scales.