Thirty years of daily data have been used to estimate the annual cycle of the large-scale 500-mbar geopotential height fields. The resulting Fourier coefficients, desribing the smooth annual cycle, have been used to study the annual cycle of the planetary-scale northern hemisphere seasonally forced waves. Monthly mean maps of the first three waves are presented, as well as the annual cycle of the eddy momentum flux caused by these waves. It is shown that, during the winter circulation regime, zonal wave number 2 transports momentum toward the south, while wave numbers 1 and 3 transport momentum toward the north. During the summer circulation regime, the fluxes as weak. It is found that there is a connection between a suddenly increased equatorward momentum flux for zonal wave number 2 in late November and the onset of the winter circulation regime.