There are projected to be many fewer cool days (days with minimum temperatures less than 28°F), with decreases of 30 days or more per year by mid-century.

The largest decreases in number of cool days are expected in western areas of Montana and Wyoming, with much of this area expecting 35-50 fewer days with a minimum temperature below 28 degrees by the middle of the century. Nebraska and the Dakotas are expected to experience 20-30 fewer cool days.