The seasonal-latitudinal tidal structures of O, N2 and total mass density in the thermosphere for minimum and maximum levels of solar activity are investigated by using a theoretical model and accelerometer data from the Atmoshpere Explorer, C, D, E, and Air Force S3-1 satellites. According to theory, oxygen variations are strongly influenced by seasonal differences in the winds, whereas N2 responds primarily to temperature, which has a different seasonal dependence than the winds. The tidal variation of total mass density is complicated by its dependence on the relative amplitudes and phases of the O and N2 variations. The net effect is that rather complicated and different seasonal-latitudinal tidal structures are predicted to occur. Some representative theoretical profiles are presented. Theoretical height structures of diurnal amplitude and phase of O and N2 near the equator are in good agreement with recently published tidal analyses of Atmosphere Explorer E mass spectrometer data. Tidal analyses of the accelerometer data verify the shift to later times of the diurnal phase of total mass density from the equator to mid-latitudes in the lower thermosphere as predicted by theory.