Understanding Our Current Drought

Drought conditions are not experienced uniformly across California. Water users experience drought differently, depending on the type of water supply being accessed and the user’s ability to manage drought impacts.

Dry conditions can quickly lead to impacts for ranchers grazing livestock on non-irrigated rangeland or for rural residents relying on private wells for groundwater. In contrast, large urban water agencies with multiple water sources have the potential to weather multiple dry years. As drought conditions persist, eventually all water users experience impacts.

Risk of drought impacts occur when precipitation is below normal levels. Risk also increases when dry conditions combine with above-average temperatures, as has been observed in California’s recent droughts.

Maps on this page show three different indicators that provide a measure of the severity of the current drought in California. The use of multiple drought indicators is preferred given the diversity of California’s water users. The three indicators displayed here include:

"Weather drought indicator" – Indicator represents a measure of atmospheric moisture supply and demand over time by integrating the effects of precipitation, temperature, and evapotranspiration.
"Runoff drought indicators" – Indicators represent the effects of changes in atmospheric conditions on a watershed’s snowpack and runoff.
"Water supply drought indicators" – Indicators represent the amount of surface and groundwater storage available.

Weather Drought Indicator -

California is experiencing extreme dryness. Low precipitation combined with higher temperature is resulting in dry conditions throughout the state. This map integrates measures of precipitation, air temperature, and evapotranspiration, key factors in California’s water cycle.

Note: Map shows the Standard Precipitation-Evapotranspiration Index (SPEI). Source: Western Regional Climate Center (https://wrcc.dri.edu/wwdt/index.php?folder=spei12)