Ocean waves interact with the solid Earth, generating two dominant signals called microseisms, which carry information about energy exchange between different Earth systems. Here, we show that 6C (three-component translation and three-component rotation) observations are able to resolve their seasonal azimuthal variations. We employ the rotational motions retrieved by a small seismic array at the Pinon Flat Observatory (PFO) to investigate the two dominant microseismic sources: primary (10-20s) and secondary (3-10s) microseisms. The primary microseismic Rayleigh waves show strong seasonal variations as expected, whereas the secondary microseismic Rayleigh waves show slight seasonal changes. In contrast, we find that secondary microseismic Love waves exhibit considerable seasonality. This discrepancy from the secondary microseismic Rayleigh waves provides us with new insights into the generation mechanism of Love waves. In addition, the results suggest that rotational motions of primary microseisms retrieved by the seismic array are more sensitive to atmospheric pressure-induced ground deformation.