Spending too much time indoors got you down? No problem, Great River Road Trail in Clayton County, Iowa is the outdoors at it's best. Iowa is a great place for hikers. During the summertime months at Great River Road Trail highs are generally in the 80's with nighttime lows in the 60's. Highs through the winter are commonly in the 20's; overnight lows in the 0's for Great River Road Trail. The annual rainfall here at Great River Road Trail is about average. The month of August is the wettest with most of the rain, and the driest month is January.