Weather in Yellowstone

Cup fan wrote:
Looking at going to Yellowstone the last week of May. I understand that the weather anywhere is a crapshoot. But I was wondering, as a general rule of thumb, what to expect. Would like to hear from some folks who have been there around the Memorial Day time frame, and what kind weather you experienced.

We have reservations for the end of May, a buddy of mine that's works up there said he thought it was the best time to go. Its been a very mild winter as well so hopefully we will be Okay. I'm not worried about it. We are staying at Madison campground in the park itself from the 25 -29th of May. Fishing opens up that weekend too in the Maddison river I was told when I made our reservations. I couldn't find what I wanted online so I called and sure enough they had sites that were not shown to be available on line.