If you're considering climbing it in October, you would be well advised to bring along some cold weather equipmet. It's been known to drop well below freezing overnight!
Here's a link that should provide a little more info on the hike.
Click here.
I will add this though. There is an old saying that says, if you visit Japan and do not climb Mount Fuji, you are destined to return. I know of several people who were stationed there in the military, some for a few years, that did not climb it while they were there. Almost to a man, each one had returned at one time or another, just to do the climb.
Randy