To clarify the characteristics of global sea surface temperature (SST) products, we have compared the Reynolds product with four other products: the Center for Atmospheric and Oceanic Studies (CAOS) SST, the microwave optimum interpolation (MWOI) SST, the merged satellite and in‐situ data global daily (MGD) SST and the real time global (RTG) SST. Furthermore, we have validated these five products with SST data observed by moored buoys. The CAOS SST and the MWOI SST show significant underestimation in several regions. The underestimation is related to the characteristics of the original microwave data. It should be noted that the MGD SST provides the best statistics, although the high‐frequency variations are removed by a low‐pass filter. Moreover, we have investigated the impact of the differences between the SST products on estimated latent heat flux. In regions with strong SST gradients, the average differences are significantly large.