The temperatures in the region of the atmosphere between 30 and 80 kilometers have been determined from measurements of the velocity of sound in nearly vertical propagation. The sources of sound were grenades consecutively ejected from Aerobee rockets. The method of analysis of the data to obtain accurate temperatures is described, and the results are presented. The temperature data are in good agreement with balloon data near 30 km and show a maximum of about 268K at 48 km. The probable errors are less than 3 percent. There are no clear-cut seasonal effects at the latitude of the firings, 32°N, although a number of marked irregularities in temperature in individual firings was noted.