89 percent of nine western states are in some form of drought, and more than a quarter of the region is considered in exceptional drought, the worst category in the U.S. Drought Monitor.

•  Droughts leave deep bruises that may not surface for months or years. Too much heat and too little rain can cause ecosystems to collapse and hasten the spread of non-native species.

•  Over the coming decades, a warming climate will cause more frequent and intense droughts, especially in the Colorado River basin.

It develops in stages, a story that builds upon itself. A few cloudless days. Then a rain-free week. Soon a hot, dry month.

Now the hills are brown and the crops need watering — the first signs of drought

The intensely dry conditions that have settled over the American West and Upper Midwest this year are well past the brown hills stage. Nearly 89 percent of nine western states are in some form of drought, and more than a quarter of the region is considered in exceptional drought, the worst category in the U.S. Drought Monitor.