A majority of climate models suggest that precipitation in the Great Plains will increase in the winter, spring, and fall by the end of the century, but most models project that summer precipitation may decrease.

Simulated changes in summer precipitation by the end of the century range from a 37-percent decrease to a 12-percent increase, with a mean around an 10-percent decrease. The strongest agreement for drier summers occurs in Oklahoma and west Texas. The means of several climate models indicate that winter and spring precipitation may increase around 3 percent by the end of the century, with larger increases expected in the Dakotas. Under mild climate scenarios, changes are generally smaller than in more extreme climate scenarios.