Droughts can take on a regional context.
Residents of arid West Texas may cope for two or three years with little rain before acknowledging that a drought exists. In East Texas, where rainfall is plentiful, a few months of below average precipitation can heighten concerns that a drought may be coming. In a broad sense, drought occurs whenever water supplies are inadequate for human needs. Most often, these water shortages stem from a severe shortage of rainfall but they can be exacerbated by high water demands and inadequate distribution systems. Rainfall does not need to be below average for droughts to take hold.