The role of vibrational-rotational interaction and centrifugal distortion in a molecule, as well as its polarizability anisotropy (for Q branch) in the accuracy of determination of the rotational temperature from Raman spectra is investigated. It is shown that neglect of these effects can give a noticeable systematic error in the temperature determination. Analytical equations are obtained for systematic errors of temperature determination in the case of using lines of the O-, S, and Q branches for the vibrational bands v -> v, v + 1. The results obtained are illustrated with data on nitrogen and oxygen molecules as an example.