Changing rain and snowfall patterns, combined with other environmental and socio-economic factors could alter inland flooding risk in many states. These floods put people at risk and can damage buildings and infrastructure, especially those in low-lying areas. Our analysis assesses each state’s threat from inland flooding based on the severity of high runoff events and the number of people living in areas at risk of a 100-year flood (which has a 1 percent chance of occurring every year).