The effect exists at all latitudes where a sunrise or sunset actually occurs, but the precise direction (how much N or S of W or E) will vary with latitude (as well as date, of course). The extreme case is the point near the pole where the sunrise or sunset is barely averted, where the position of the sun will be due N or S (neither W nor E since it is simultaneously rise and set); even at the equator, however, the sun will be somewhat N or S of W or E. The exception is when sunrise or sunset occurs at the precise moment of equinox; then all latitudes will experience a sunrise or sunset, and all (except at the poles themselves where these directions don't exist) will experience it as due W or E. (All exact claims are theoretical assuming a perfectly spherical Earth, but the general phenomenon should occur any time that's not very close to the equinox and any place that's not right up next to a cliff or something.)