first, I agree whole heartedly with Bravak.
I have also lived and hunted extensively in both states. I was in colorado this past week fly fishing and the highs were in the mid 60's, low's in the lower 30's. Chances are that you will get thunderstoms daily. I've hunted elk on opening day in wyoming in an absolute blizzard. Generally your highs will be in the 50's and lows in the 20-30 range. Definitely take plenty of water. I recommend a purifier or filter as well. If you give me a location in wyoming where you will be hunting I can get you more details. Good luck.