Four determinations of neutral thermospheric temperature from data taken with instruments aboard the AE-C spacecraft have been compared during the circular orbit phase in late December 1974 and January 1975 when the satellite altitude was near 160 km. These temperatures are found to be in overall agreement to within about 10% during periods of low magnetic activity (Ap<12). The methods are based on: (1) analysis of the satellite spin modulation of N2 density; (2) analysis of the ion temperature; (3) to match measured N2 and Ar densities assuming fixed boundary conditions at 120 km. Systematic differences are observed such that the 'argon temperature' increases the most from winter to summer and ion temperature the least.