Meteorological Drought

Meteorological drought is caused by lack of precipitation. It is defined by how dry a region is compared to normal, and how long the dry period lasts. Meteorological drought is region specific: there is no universal minimum value for the rainfall shortage or minimum duration of the dry period.

California was in severe drought during its latest drought cycle from 2011–2017. This graph shows the reduced monthly rainfall in 2013, compared to the state’s average rainfall over 30 years.