The standard technique for computing total column ozone from a balloonsonde measurement includes an extrapolation of the measured ozone profile to altitudes above the balloon burst altitude. This total column calculation can be improved by using a monthly average ozone climatology based on ozone profile measurements from the solar backscattered ultraviolet instrument on the Nimbus 7 satellite. For each month and 10¿ latitude zone we provide the column ozone above 30 distinct pressure levels in the middle and upper atmosphere (from 1 through 30 mbar) that can be added to the measured balloon profile. Use of this climatology reduces the uncertainty in the column ozone estimate when the sonde data are compared with simultaneous Dobson observations at Boulder and at Mauna Loa.¿ 1997 American Geophysical Union