Originally Posted by
spinnaker
... What is the weather like in September?...
i backpacked through that area and Tetons and rest of Wyoming in sept/oct. in yellowstone (where some say there are only three seasons, fall, winter and spring) i encountered eight inch snowfalls and sub 30 degree temps. but not for long. the rest of Wy., once i got over Togwotee Pass was great. of course a much more reliable source of average temps can be found elsewhere on the internet.