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Droughts in California

Percent area in U.S. drought monitor categories

The historical and ongoing droughts in California result from various complex meteorological phenomena, some of which are not fully understood by scientists.

Drought is generally defined as "a deficiency of precipitation over an extended period of time (usually a season or more), resulting in a water shortage."[1]

A lack of rainfall (or snowfall) or precipitation in meager quantities, higher than average temperatures and dry air masses in the atmosphere commonly underlie drought conditions; these natural factors are further complicated by increases in populations and water demands. Since the California water supply is attained from numerous sources, fulfilled by varied and intricate weather patterns, there is no one cause of drought. California is not only the most populous state and largest agricultural producer in the United States, it is also the most biodiverse;[2] as such, drought in California can have a far reaching economic and environmental impacts.

There are five major technical categories of drought: (1) Meteorological, (2) Agricultural, (3) Hydrological, (4) Socioeconomic, and (5) Ecological. A meteorological drought may be short lived without causing disturbance; but when longer lasting may enter other categories according to its impacts.[3][4] In addition to technical categories, the Governor Newsom administration introduced in 2023 the concept of a political drought, where state public policy actions would need to continue even after short-term drought conditions may have ameliorated.[5]

Precipitation in California occurs mostly from November to May, with the vast majority of rain and snowfall across the state occurring during the winter months. This delicate balance means that a dry rainy season can have lasting consequences.

  1. ^ "Drought Basics". Drought.gov. National Integrated Drought Information System, NOAA. Archived from the original on September 20, 2022. Retrieved September 16, 2022.
  2. ^ "Biodiversity – The Variety of Life on Earth". wildlife.ca.gov. California Department of Fish and Wildlife. Archived from the original on September 20, 2022. Retrieved September 18, 2022.
  3. ^ "Types of Drought". drought.unl.edu. National Drought Mitigation Center | University of Nebraska. Archived from the original on September 20, 2022. Retrieved September 17, 2022.
  4. ^ "Definition of Drought". www.ncei.noaa.gov. NOAA | National Centers for Environmental Information (NCEI). Archived from the original on September 20, 2022. Retrieved September 17, 2022.
  5. ^ Cite error: The named reference lat20230222 was invoked but never defined (see the help page).