National Weather Service United States Department of Commerce

What Is Drought? Drought is a deficiency in precipitation over an extended period. It is a part of normal climate variability in many climate zones. The duration of droughts varies widely. Drought can develop quickly and last only for a matter of weeks, exacerbated by extreme heat and/or wind, but more commonly drought can persist for months or years.

There have been at least three major U.S. droughts in the last 100 years. Two of these, the 1930s Dust Bowl drought and the 1950s drought, each lasted 5-7 seven years and covered large areas of the country with significant impacts. Although hurricanes and tornadoes are more dramatic, droughts are among the most costly weather related events and the most far reaching. From 1980–2020, there were 285 weather/climate disaster events with losses exceeding $1 billion (CPI-Adjusted) each to affect the United States.

Drought may require safety precautions just like other weather hazards. Dry conditions often lead to brush fires or wildfires. Local officials may ask that you not burn brush or trash during dry conditions and comply with other safety precautions. In extreme fire conditions, officials may issue mandatory evacuation orders to protect your life. Always follow these directives. They could save your lives and the life of your family.

Types of Drought

Meteorological drought is based on the degree of dryness (rainfall deficit) and the length of the dry period.

Hydrologic drought is based on the impact of rainfall deficits on the water supply such as stream flow, reservoir and lake levels, and ground water table decline.

Agricultural drought is based on the impacts to agriculture by factors such as rainfall deficits, soil water deficits, reduced groundwater, or reservoir levels needed for irrigation.

Socioeconomic drought is based on the impact of drought conditions (meteorological, agricultural, or hydrological drought) on supply and demand of some economic goods. Socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related deficit in water supply.