The long term behavior of Kelvin waves is studied, using monthly data on the variance of zonal wind and temperature at Canton Island, for the period September 1954-March 1965. Increased variances are found to accompany the descent of the westerly wind regimes associated with the quasibiennial oscillation. This is indicative of increased Kelvin wave activity within the shear zone which marks the leading edge of the westerlies. There is evidence of a convergence of westerly momentum within the shear zone, which supports the hypothesis that Kelvin waves may play an essential part in the momentum budget of the quasi-biennial oscillation.