Precipitation in winter and spring is expected to increase 10%–30% by the end of this century. Summer precipitation is expected to vary, ranging from no change under a low emissions scenario to a 10%–20% reduction.

There is uncertainty between different climate scenarios for future precipitation projections in the Great Plains. Generally, there is a south-to-north gradient in annual precipitation projections, with increases projected north of the Nebraska-South Dakota border. However, annual precipitation and streamflow projections show only modest changes. The region already experiences considerable variability in precipitation each year, which contributes to a higher degree of uncertainity about future potential for flooding and drought.