Hydroxyl airglow measurements during the ALOHA-93, ALOHA-90 and ANLC-93 campaigns are used to evaluate features of the temperature variation of the mesopause region. Each campaign shows a persistent pattern in the averaged local time variation of temperature with peak-to-peak amplitudes of 5 K to 15 K, suggestive of the presence of tidal modulation. The nightly temperature variance, after detrending to remove low frequency variations due to tides, is shown to be significantly less during the Hawaiian campaigns than during the ANLC-93 and other campaigns at sites where significant orographic excitation of waves might be expected. ¿ American Geophysical Union 1995