the best route
is usually to get south as quickly as possible. It doesn't warm up till you reach around the latitude of San Diego
. On my passage
, a rhumb line course was the quickest to the islands but took 10 days to get far enough south to get warm and see the sun leaving from SF. Typically in the summertime, the high makes a southerly course the fastest but not when I sailed.
Because of the crappy weather
in PNW, I wouldn't want to leave before May. If you chose to leave earlier, keep a weather eye out for the lows sweeping across the North Pacific
. Might want to hop from harbor to harbor if you decide to leave before May. That way you can take advantage of weather windows and ride out the storms tucked into a nice harbor. Once past Point Conception, you are usually out of the nasty weather and it's starting to warm up.
The return trip is best done before the end of September. You'll have to sail up to about 50N to get around the high. That gets you into any bad weather generated in the North Pacific
. By the end of October, the winter weather pattern of closely spaced low pressure systems marching across the north Pacific is pretty well established. Besides, it's damned awfully cold vice just damned cold as it in the late summer months.