Idaho is a great place for hikers. Ryegrass Trail is a location that is rather arid generally. June is when you get the most rain here; October on the other hand is the driest. At Ryegrass Trail through the summer months highs are in the 80's with night lows in the 50's. Highs all through the winter are typically in the 30's, and nighttime lows in the 0's for Ryegrass Trail.