Hunted that general area last year. Highs in the upper 50’s to low 60’s, lows in the high 30’s to low 40’s. It was cool and rainy most of the week. When we were leaving they got a decent snowstorm, so be prepared for it.
Two years ago I was hunting WY in October. It was a hot day. I hunted in a T-shirt. Mid 80s that day. The next day it was 25 with 65 mph winds. Like said above, pack like a woman. Better to have it and not need it than to need it and not have it. Last year, I experienced warm, sunny days, then wind and snow, then back to 70 degree days all in a a nine-day stint.
Hot, cold, rainy and windy. Then the rain turns to sleet and snow. 2nd day the roads wash out by the 5th day it's back to 72* during the day and 52 at night. Very unpredictable weather, except the wind. Wind in Wyoming seems to be a constant companion
AGree with what has been said. We hunted a general unit outside of Cody area last October. It was all over the place. The day I flew in had enough snow to shut the airport down due to ice at night. The next day was freezing cold and blowing. the day after was like an east coast spring day. On the hunt we had 50's, 20's, 60's, etc. All over the place weather wise.
I hunt up there each year. Like others have said, pack like a woman. Plan on a 50 degree temp swing and you'll be fine. Stay off the 2 tracks if it rains and just walk a little further. Those ruts people put in the roads stay for a long long time once the roads dry out, almost ruining the roads until they can be grades out again.