In this paper, we present a statistical validation of the DSCOVR solar wind data in the operational space weather archive. The DSCOVR observations of the interplanetary magnetic field (IMF), solar wind velocity, density, and temperature were hourly averaged and compared to measurements from NASA’s ACE and Wind spacecraft. Hourly averages, in general, show good correlations between the satellites for the IMF, solar wind velocity GSE v_x-component, and density. During the period covered by this study (spanning from late July 2016, when DSCOVR went operational, to the end of 2020), the DSCOVR products show no clear evidence of permanent degradation. However, for plasma parameters there were periods of disagreement with ACE and Wind. The correlation coefficients (Pearson’s r) calculated over the entire study period were similar or the same between DSCOVR versus Wind and DSCOVR versus ACE. For comparisons between DSCOVR and Wind, the IMF B_x and B_y GSE r were 0.94 and 0.96, respectively, while r for the IMF GSE Bz-component was 0.88. For solar wind velocity, r was found to be 0.96 for the GSE v_x-component, compared with 0.30 for v_y and 0.33 for v_z. For density, r was found to be 0.84. DSCOVR density observations tend to overestimate compared to Wind values when the solar wind densities are low (below ∼5 /cc), while agreement between the two spacecraft on IMF measurements tend to increase with decreasing spatial separation.