A year of precipitation consists of many wet and dry periods and it is sometimes difficult to see the long-term (yearly) precipitation climatology. The attached map shows the departure from normal (in percent) for the total annual (2010) precipitation for the conterminous U.S.
Northeastern Nebraska had widespread flooding from repeated heavy rains in May and June 2010, but that extreme wet spell is somewhat hidden when taking a look at the annual totals.
Much of the U.S. in 2010 experienced below normal precipitation (yellow and brown colors). The two primary very wet locations (blue and purple colors) in 2010 were the Iowa to North and South Dakota region and the Southern California to Nevada region.
Create your own climate maps at our High Plains Regional Climate Center. http://www.hprcc.unl.edu/