Satellite observations of sea surface salinity (SSS) have been validated in a number of instances using different forms of in situ data, including Argo floats, moorings and gridded in situ products. Since one of the most energetic timescales of variability of SSS is the seasonal, it is important to know if satellites and in situ gridded products are observing the seasonal variability correctly. In this study we validate the seasonal SSS from satellite and in situ products using observations from moorings in the global tropical moored buoy array. We utilize 6 different satellite products, and two different in situ gridded products. For each product we have computed seasonal harmonics, including amplitude, phase and fraction of variance (R2). These quantities are mapped for each product and for the moorings. We also do comparisons of amplitude, phase and R2 between moorings and all the satellite and in situ products. Taking the mooring observations as ground truth, we find general good agreement between them and the satellite and in situ products, with near zero bias in phase and amplitude and small root mean square differences. Tables are presented with these quantities for each product quantifying the degree of agreement.