I traveled that route just a bit earlier (April-May) and found the prevailing winds helped me along for most of the route, increasing in strength the further south I went. In Oregon and northern California some days the wind blowing south was very strong and caution had to be exercised not to be blown into traffic etc. As others have said, going south has you on the coast side of the road. You don't want to be constantly crossing the hwy for a good view.