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Regional Drought Update Date
January 21, 2021
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Drought Status Update

Drought Status Update for California-Nevada

DEWS Regions:
Update Status:

NIDIS and its partners will issue future drought updates as conditions evolve.

Drought conditions in California and Nevada are at a crossroads as the window is closing for precipitation.

  • Moderate-to-extreme drought remains across California and Nevada, which typically receive about half of their precipitation in December through February.  
  • Recent storms have brought some relief to Southern California with widespread precipitation on the horizon. This may alleviate some drought conditions but is likely not enough to remove long-term drought conditions and impacts. 
  • Low snowpack (i.e., snow drought) and decreasing reservoir levels in the Sierra are leading to below-normal total water storage (natural and human-built). Soil moisture remains low. 
  • Preparation for continued drought impacts (e.g., pasture conditions, water supply, fire risk) should be considered, especially in the driest areas. A precipitation regime change may improve conditions, but based on climatology, a water deficit in the region will continue. This update includes data as of January 20, 2021. 
Current Conditions
U.S. Drought Monitor Conditions: California-Nevada | January 19, 2021

U.S. Drought Monitor Categories

Main Stats
of California is experiencing Moderate to Exceptional Drought (D1-D4)
30.4 Million
people in California are in Moderate to Exceptional (D1 - D4) Drought
of Nevada is experiencing Moderate to Exceptional Drought (D1-D4)
2.7 Million
people in Nevada are in Moderate to Exceptional (D1 - D4) Drought

Current Conditions

  • Drought conditions, according to the U.S. Drought Monitor, over the past few weeks stayed the same or worsened, primarily in central California. Long-term precipitation deficits from 2020 remain.
  • The La Niña pattern that developed in the tropical Pacific in Autumn 2020 remains firmly in place. Over the historical record, La Niña tilts odds toward wetter water years in the Pacific Northwest and drier water years in the Southwest U.S. There is large uncertainty in the northern parts of California and Nevada.
  • Atmospheric rivers earlier this month tracked towards the Pacific Northwest and a small area of northwestern California and, in recent days, Southern California. California’s 8 station index and the Reno/Carson City region are near 17%–18% of normal cumulative water year totals.
  • Snow water equivalent (SWE) values remain below normal across the Sierras and the Colorado River Basin. According to the U.S. Department of Agriculture's Natural Resources Conservation Service, some stations are as low as 25%–50% of 1981–2010 median values. Statewide this averages to just 21% of the April 1 average, indicating widespread snow drought.
  • Reservoir levels are below normal in the northern, central, and southern Sierras, and Lake Tahoe is approaching its normal levels. Evaporative demand over the 3 months has been high, and soil moisture and shallow groundwater are low throughout the region.
  • The odds of reaching normal precipitation for the water year remain between 10%–30% throughout much of California and Nevada.

Percent of Normal Precipitation

Two images show the the percent of normal precipitation for California and Nevada through 1/20/2021. For the past 14 days (left image), most of CA-NV shows less than 25% of normal except for a small area of northwest California (75%-125%) and southeast California (up to 400%-800%). On the right, the percent since the start of the water year shows most of CA-NV below 50%-70% of normal with small areas between 80%-90%.
Percent of normal precipitation for the last 14 days (left) and since the start of water year (right). Source: High Plains Regional Climate Center.

Snow Water Equivalent Percent of Median

A map of the western U.S. showing the percent of 1981-2020 median snow water equivalent values from the NRCS from 1/20/2021.  The states of CA, NV, UT, AZ, NM, CO are shown with a color bar from 0% (red) to >200% (blue). SNOTEL stations with a 20 year record and watershed basins are shown. SWE in the region is primarily between 0% and 75%, including the Sierras (25%-75%).
Snow water equivalent percent of 1980-2010 median. For an interactive version of this map, please visit NRCS.

Evaporative Demand Drought Index (EDDI): 1 Month, 3 Month, 6 Month

A map of California-Nevada showing the Evaporative Demand Drought Index (EDDI) at a 1-month time scale as of 01/14/2021. County lines are shown and a colorbar scale ranges from ED4 (red, 100% drought) to EW4 (blue, 0%). At 1-month, EDDI show values of ED0-ED4 in southern CA-NV and EW1-EW3 near northeast CA.
1-Month Evaporative Demand Drought Index (EDDI). Source: NOAA/Earth System Research Laboratories, Great Basin Dashboard.


A map of California-Nevada showing the Evaporative Demand Drought Index (EDDI) at a 3-month time scale as of 01/14/2021. County lines are shown and a colorbar scale ranges from ED4 (red, 100% drought) to EW4 (blue, 0%).   At 3 months, the EDDI shows values of ED0-ED4 across most of CA-NV except for northernmost NV and near the northern CA-NV border.
3-Month Evaporative Demand Drought Index (EDDI). Source: NOAA/Earth System Research Laboratories, Great Basin Dashboard.


A map of California-Nevada showing the Evaporative Demand Drought Index (EDDI) at a 6-month time scale as of 01/14/2021.  County lines are shown and a colorbar scale ranges from ED4 (red, 100% drought) to EW4 (blue, 0%).   At 6 months, the EDDI shows values of ED0-ED4 across all of CA-NV with ED4 conditions predominant.
3-Month Evaporative Demand Drought Index (EDDI). Source: NOAA/Earth System Research Laboratories, Great Basin Dashboard.

California/Nevada Soil Moisture Drought Intensity: January 19, 2021

A map of California-Nevada shows soil moisture drought intensity from 1/19/2021. Exceptional Drought (D4, 12.2%) is present over the CA central coast, the CA-NV border near the Southern Sierra, and across S. NV. D0-D2 is present over much of the remaining area.

Soil Moisture Drought Intensity, valid January 19, 2021. Source: UCLA Drought Monitor.

Water Storage in the Northern, Central, Southern Sierra

Three time series graphics showing water storage tracking (reservoirs + snow pack) for Oct 1, 2020 thru Oct 1, 2021 for 3 parts of the Sierra and a map of California-Nevada of the locations of the reservoirs broken down by north (blue), central (yellow), southern (red) Sierra. Each time series graphic shows the 2000-2015 regional reservoir normal and reservoir + snowpack normal. In all 3 parts of the Sierra, reservoir normals are below normal (well below in the North Sierra) and reservoir + snowpack are below normal.
Water storage compared to 1981-2010 below normal in the Northern, Central, and Southern Sierra through January 19, 2021. Source: CNAP Water Storage Tracking.

Odds of Water Year 2021 Reaching 50%, 75%, and 100% of Water Year Normal Precipitation

These maps shows odds of water year 2021 reaching 50%, 75%, or 100% of water year normal precipitation as of Jan 1, 2021 for the western U.S.. The color bar ranges from 0% (white) to 100% (blue). Most of California and Nevada have 10%-30% odds of reaching 100% of normal precipitation and have 30%-80% odds for reaching 75% of normal precipitation.
The odds of reaching normal precipitation based on historical water year totals. The dry start to the water year means the odds of reaching normal precipitation is between 10%-30% throughout the region. Learn more about the product at CW3E website

Drought Impacts

  • CMOR drought reports continue to show reports of those with 10-20 years experience in their regions comparing current conditions to 2014-2015. Example: 
    • Placer County, CA, 1/11/21, Moderately Dry: We typically don't feed hay in November/December, but we did this year. May have to feed hay again late winter/early spring. Since 1994, I've only seen it this dry in January in 2014 and 2015.
    • Humboldt County, NV, 1/14/21, Moderately Dry: Increased hauling of water to BLM pasture areas over the last 4 out of 5 years. But prior to this period only three times out of 20 plus years was the ranch needing to haul water to BLM pastures.
    • White Pine County, NV, 1/13/21, Severely Dry: Precipitation received 1-2 years ago filled reservoir supporting the ranch. Therefore there are no impacts on production this year but could occur in the future possibly next year if drought continues.
  • Many recreational sites, including ski resorts, are experiencing the impacts of low snow and moderate to extreme drought conditions. Other drought impacts include farmers considering selling cattle and potential for a worse than average wildfire season.
  • The 2020 USDA secretarial drought designation map shows much of California-Nevada as primary/contiguous designations. Learn more about crop and livestock areas in drought here and here

U.S. Ski Resorts in Drought

Map of U.S. ski resorts and their current drought conditions. The ski resorts in CA-NV are all in drought, ranging from D1 (moderate drought, tan) in southern CA, to D2 (severe drought, orange) in the central Sierra, to D3 (extreme drought, red) in the southern and northern Sierra, to D4 (exceptional drought, dark red) in southern NV.
Map of U.S. ski resorts experiencing drought, including those in CA-NV. 

Report Your Drought Impacts

Drought & Climate Outlook


NOAA’s ENSO alert system status is currently a La Niña advisory and is likely to continue through the Northern Hemisphere winter 2020–21 (~95% chance during January–March), with a potential transition to ENSO-neutral during the spring of 2021 (55% chance during April–June). For more information, please check out the NOAA ENSO blog.

The Western Regional Climate Center recently developed a handout about the La Niña impacts for the West. Check it out to see how La Niña historically has affected your region.

Seasonal Drought Outlook

The seasonal drought outlook shows drought persistence over much of California-Nevada with development likely in coastal southern California. Upcoming precipitation is not likely to alleviate long term drought conditions with the exception of potential drought improvement to far northwestern California due to recent and upcoming precipitation.

Climate Prediction Center Seasonal Drought Outlook

NOAA's Climate Prediction Center's Seasonal Drought Outlook is issued monthly on the third Thursday of each month, predicting whether drought will emerge, stay the same, or get better in the next three months. This map predicts that drought will remain but improve in northwest CA and that drought will develop in southwest CA through April 30. Drought conditions are expected to persist throughout Nevada.
U.S. Seasonal Drought Outlook for January 21 - April 30, 2021. Source: National Weather Service Climate Prediction Center.

Temperature & Precipitation

Forecasts for the coming week show widespread precipitation across the region with potential for more towards the end of the month. The NOAA National Weather Service Climate Prediction Center's January 26-February 1 forecast shows an increased chance (greatest chances the farther north) of wet, cool conditions with potential atmospheric river(s). Forecasts are yet developing. Seasonal forecasts show a return of increased odds of a “typical” La Niña pattern and a dry southwest. 

California/Nevada 6-Day Precipitation Forecast

Map of California-Nevada showing 6-day gridded forecast precipitation (inches). Highest values are greater than 1.5 inches (yellow) over the Sierras, southern CA, and northwest CA, with the lowest values in the southern CA deserts and northern NV.
6-day (4 am PST Jan. 21 to 4 am PST Jan. 27) gridded forecast precipitation from the National Weather Service California-Nevada River Forecast Center.

Climate Prediction Center 8-14 Day Outlooks

Climate Prediction Center 8-14 day temperature outlook, valid for January 28 - February 3, 2021. Show probability of below-normal temperatures throughout California and Nevada.

Climate Prediction Center 8-14 day precipitation outlook, valid for January 28 to February 3, 2021. Shows probability of above-normal precipitation across most of California and Nevada, with equal chances of above- and below-normal precipitation in the southernmost part of California.
January 28 - February 3 temperature outlook (top) and precipitation outlook (bottom). A = chances of above-normal; EC = equal chances of above, below, normal; B = chances of below-normal. Source: National Weather Service Climate Prediction Center. How do I interpret these graphics? 

Atmospheric River Conditions

This figure shows 2 graphics, a (left panel) backwards time series (X-axis) of probability of >250 kg/(ms) of integrated vapor transport (i.e., atmospheric river) vs latitude (y-axis) and (right panel) map of the western U.S. with bar graphics of similar information. High odds of high integrated vapor transport are currently impacting S. California and potentially all of California (best odds in N. CA) near Jan 27-Jan 30.
CW3E’s atmospheric river landfall tool shows the probability (i.e., percentage of ensemble members) that show atmospheric river (AR) conditions along the U.S. West Coast. Near the end of the month there are potential AR conditions headed for the West Coast, but intensity and location information is still developing. See CW3E's website for more information and forecast products.

Drought Early Warning Resources

California     Nevada     California-Nevada DEWS

Prepared By

Amanda Sheffield
NOAA/NIDIS California-Nevada DEWS Regional Drought Information Coordinator

Julie Kalansky
Program Manager, California-Nevada Applications Program (NOAA RISA team)

Special Thanks

This drought status update is issued in partnership between the National Oceanic and Atmospheric Administration (NOAA) and the California-Nevada Applications Program (CNAP), a NOAA RISA team, to communicate the current state of drought conditions in California-Nevada based on recent conditions and the upcoming forecast. NIDIS and its partners will issue future drought updates as conditions evolve. 

Register here for the next California-Nevada Drought & Climate Outlook webinar on Monday, January 25 at 11 am PST.