I have not been there in October. Weather-wise, it looks like the highs will be in the mid-50's and the lows will be in the mid-40's. Where this comes into play is Misogi, a purification ritual that we usually do in the Pilchuk river that runs next to the Shrine. (See http://www.tsubakishrine.com/misogi_shuh
It will be good to get back there. It has been too long.