The UVES echelle spectrograph of the Very Large Telescope at Cerro Paranal in Chile provides high-resolution spectra in the wavelength regime from 300 to 1100 nm with a maximum simultaneous wavelength coverage of about 400 nm. Since UVES has been regularly operated since April 2000, thousands of spectra originally taken for astronomical projects are available to study airglow variations on a time scale longer than a solar cycle. Taking data from two set-ups centred on 760 and 860 nm, we measured line intensities for several OH bands in order to derive band intensities and rotational temperatures for different upper vibrational levels v' as a function of solar activity and observing date. The results are compared with those derived from emission and temperature profile data of the radiometer SABER on the TIMED satellite taken since 2002. The discussion will also include an estimation of the contribution of non-thermal effects to the observed trends in the rotational temperatures. The OH intensities can be compared with UVES measurements of atomic oxygen and sodium lines. In agreement with the SABER data, the long-term variations in OH intensity and temperature derived from UVES data are dominated by the solar cycle, whereas secular trends are weak or even absent.