The later you leave for the mainland in the summer, the less far north you'll have to go to catch the westerlies. The Pacific High moves south as the summer progresses so you don't have to go as far north to get around it. I should say, that is in a normal year. This last summer the high never moved south and the rhumb line was the best course out to the Islands and boats going back were heading up to 50 degrees to get around it. Expect temps to stay below 60 degrees till you reach the latitude of San Diego
. Thought it would never warm-up on my rhumb line trip last summer.
Sailing to the Islands isn't too bad a trip even in the dead of winter once you get south of the lows marcing across the Pacific. Sailing back, anything past late September is asking for it. Even in the summer you can get interesting weather
. The single
handed TransPac boats in '08 got a pasting on the way back in August and one boat was abandoned. Talked with a guy who sailed a 38' boat back in January and had a delightful, though chilli, sail. He used a weather service
and waited for more than a month for the right weather pattern to develop.