Correlation and linear regression analyses of the variations in the mean stratospheric (15--50 km) and the mean mesospheric (50--80 km) temperatures with sunspot number variations during a complete solar cycle (1971-1982) have been made over the equatorial rocket launching station, Thumba (8 ¿N, 77 ¿E), India. The results were treated with the Student's t test. The study revealed that practically no correlation seems to be present between temperature and sunspot number variations in the stratosphere, but strong, positive, and highly significant correlation and regression coefficients are found in the mesosphere. A change in mesospheric mean temperature of 14 K was seen during the period when the solar cycle passes from the minimum to the maximum. A vertical profile study indicated that solar-related temperature variations are strong in the middle mesosphere. Higher correlation and regression coefficients values were reported during the equinox season, and lower during the summer season.