Besides rain, what type of weather is to be expected for the San Juan Islands in Sept/Oct? Trying to decide what to pack...

PLEASE post a more descriptive headline than "weather." Thousands of people who have no clue about the San Juan Islands will unnecessarily waste time on this post.

Sept is USUALLY beautiful, Oct can be "iffy" So you always do the "layered" thing. Example: on the ferry in the San Juans usually need coat or heavy sweater with scarf. Get off at one of the islands (out of the wind) you can peel down to sleeveless blouse or T shirt. Sweats-pants & shirts are real useful.I always include some less casual for dinner, but dress code is real relaxed at most resturants.
I ALWAYS take parka-rain poncho. Out of 7 trips used it 6 times.Often it is just a drizzle and the sun pops out in afternoon These months are our favorite times AND EVEN Oct is a little less than perfect weather it is usually much less crowded than the first 3 weeks of Sept.
Whatever the weather just going there is a wonderful trip

Jim: Thanks for the advice on descriptive headlines - sorry I am not a seasoned chatter. Seems like I upset you - sorry about that. Will take your advice.

Here's a pretty good weather website:

http://www.wunderground.com

You enter world city, it will give you current conditions.

I believe there's 'historical' stats you can click on.....tho' the San Juans might not be one of them.