Skip to main content
U.S. flag

An official website of the United States government

Map of the California-Nevada DEWS region
Site Section
Drought Early Warning System


Drought in California and Nevada is a common occurrence that can last for multiple years. The regional climate is characterized by a distinct dry season (approximately May to September) and wet season (October to April) defined by a few large precipitation events. Additional peaks in precipitation can occur, such as summer precipitation in southern Nevada due to the North American monsoon. Topography within the region creates a diverse set of climate conditions, from the snowy peaks of the Sierra Nevada Range to the Mojave Desert, to the mountains and valleys of the Basin and Range. Given the extreme variability, both spatially and temporally, efficiently using and effectively managing finite water resources is a high priority. Based on the many connections the two states share with respect to geography, climate, water, and drought, a joint CA-NV drought early warning system (DEWS) was developed to support enhanced drought early warning across the region and to build out NIDIS’s national drought early warning system. 

Primary contact: Amanda Sheffield, Regional Drought Information Coordinator

Regional Activities

Regional Activities Summary

The following table highlights activities in California and Nevada that are ongoing efforts related to drought, involve multiple partners, serve as a unique way to address regional drought needs, and are related to at least one of the components of drought early warning. Please contact Amanda Sheffield ( for more information about the table or to inquire about getting an activity added to the list.

Drought Early Warning System (DEWS) Components Legend

Observation & Monitoring
Planning & Preparedness
Prediction & Forecasting
Communication & Outreach
Research & Applications

Select filters to browse DEWS Activities below


The Drought Information Statement is a summary of the current state of the drought, including precipitation deficits, local impacts, outlooks, and other information. A statement is issued by the…

Key Partners
National Weather Service
Project Timeline
DEWS Components

The Native Waters on Arid Lands (NWAL) project identifies and addresses impacts of climate change on tribal farmers and ranchers in the Great Basin, Southwest, and Northern Rockies. When the COVID…

Key Partners
Desert Research Institute, University of Nevada Reno, University of Arizona, Crow Canyon Archaeological Center, University of Montana, Salish Kootenai College, USDA
Project Timeline
DEWS Components

This brief two-page quarterly report provides a summary of the previous season's weather and climate, including any extreme events that occurred and the associated impacts. The report also…

Key Partners
Western Regional Climate Center, NOAA, NIDIS
Project Timeline
DEWS Components

Observation + Monitoring

When monitoring drought, it is important to look at data across the spectrum—from the atmosphere, land surface, and water availability below the surface. The list of data and maps below has been customized for California and Nevada, and provides a snapshot of conditions across that spectrum, including streamflow, groundwater, snowpack, wildfire, and various derived indices for monitoring drought in the region.

Regional Data and Maps

The WestWide Drought Tracker (WWDT) provides fine-scale drought monitoring and climate products for the Western United States.


The California Data Exchange Center is a centralized database that stores, processes, and exchanges real-time hydrologic information on precipitation, river forecast, river stages/flow, snow, and r

This interactive tool shows California groundwater level data, including depth below ground surface, groundwater elevation, and groundwater change in elevation. 

Point maps and interactive maps of snow water equivalent, snow depth, and snow density from the Natural Resources Conservation Service (NRCS) Snow Telemetry (SNOTEL).

The National Interagency Fire Center (NIFC) curates an ArcGIS Online organization to provide a common location for online mapping during wildland fire incident support and response activities.

NOAA and its partners publish regional reports each quarter, summarizing weather, impacts and predictions.

Planning + Preparedness

There is little that can be done to influence the weather patterns that cause drought, but preparatory actions and policies can help communities cope with drought impacts. Drought planning can ensure continuity of public services and quality of life. Drought planning can be done at the local and/or state level, or integrated into existing plans (e.g., hazard mitigation planning, land-use planning).

Regional Drought Planning Resources

Document Date
May 2019

Prediction + Forecasting

When will drought affect me? How long could it last? This section includes resources for drought prediction and forecasting on what could be ahead, including the short-term (e.g., 8–14 day forecast), seasonal to subseasonal (e.g., monthly), and future climate projections (e.g., mid-century). The appropriate time scale will depend upon how this information is being used (e.g., drought response, mitigation management action, long-term planning). Weather and climate prediction is an evolving science, as researchers continue to find ways to improve models and forecasting capabilities at various time scales. 

Regional Forecasts and Outlooks

The U.S. Monthly Drought Outlook predicts whether drought will emerge, stay the same or get better over the next 30 days or so.

The U.S. Seasonal Drought Outlook depicts large-scale trends based on subjectively derived probabilities guided by short- and long-range statistical and dynamical forecasts. 

The National Significant Wildland Fire Potential Outlook is intended as a decision support tool for wildland fire managers, pr

The National Weather Service (NWS) Climate Prediction Center (CPC) produces monthly and seasonal drought outlooks based on Soil Moisture (CAS).

The Climate Prediction Center (CPC) produces temperature and precipitation outlooks for the U.S., including 6-10 day, 8-14 day, monthly, and seasonal outlooks.

The National Weather Service's Fire Weather Outlooks are intended to delineate areas of the continental U.S.

Communication + Outreach

An important component for drought early warning is communicating this information to stakeholders across the Midwest region that need this information in order to make more informed decisions. There are various ways drought information is communicated across the California-Nevada DEWS, including a bi-monthly webinar series, a quarterly climate report, and the California-Nevada DEWS email list.

Regional Communications Documents

Document Date
April 2018

Research + Applications

Research to better understand drought in California and Nevada—and its development, persistence, improvement, and interaction with other hazards—is critical to providing timely and reliable information, products, and services in support of drought early warning. This page highlights research projects that are studying drought in the California-Nevada region, with support from NIDIS.

Regional Interdisciplinary Research

California-Nevada Partners