A 10-hour wave in the mesospheric and lower thermospheric neutral winds and temperature was observed at northern high-latitude stations Resolute (74.9¿N) and Eureka (80.1¿N) by two Fabry-Perot interferometers, a Michelson interferometer, and a CCD spectrograph. The vertical wavelength of the wave was estimated to be ~53 km. An interstation wave phase comparison yielded a zonal wave number close to five. The neutral wind wave amplitude increased with altitude up to 97 km and varied little with latitude. Our observations suggest that the 10-hour wave is likely to be a result of the semidiurnal tide and the quasi-2-day wave nonlinear interaction and unlikely to be a Lamb wave. The OH emission and temperature observations are also consistent with this interpretation.