California Drought Monitor

This database will bring together different information on the status of drought and water use in California. Visualised on this site are data from the US Drought Monitor (USDM) and the US Geological Survey (USGS). This includes data on the level of drought experienced in each county as well as the water consumption for different sectors in each county. All additional county data was collected from the US Census Bureau.

Drought Levels

An area is said to experience "drought" when moisture deficits are bad enough to have social, environmental or economic effects. The USDM identifies different drought levels, based on their intensity. The highest level, "exceptional drought" is a level of drought that results in widespread loss of crops and pasture, shortages of water reservoirs and water emergencies. 

In January 2015, almost every California county had to deal with exceptional drought levels; most of these counties experienced exceptional drought throughout a majority of its land area. These drought levels have continued into the following months and led Governor Brown to declare a drought State of Emergency.

Percentage of area per county experiencing exceptional drought (January 2015)

Page Title
January 2015 Drought
July 2014 Drought
July 2014 Exceptional Drought
January 2015 Exceptional Drought
Alameda100.00%100.00%100.00%18.96%Alameda County, California
Alpine100.00%100.00%15.60%94.51%Alpine County, California
Amador100.00%100.00%20.00%98.74%Amador County, California
Butte100.00%100.00%20.00%64.54%Butte County, California
Calaveras100.00%100.00%20.00%100.00%Calaveras County, California
Colusa100.00%100.00%20.00%21.32%Colusa County, California
Contra Costa100.00%100.00%98.53%9.50%Contra Costa County, California
Del Norte14.28%100.00%0.00%0.00%Del Norte County, California
El Dorado100.00%100.00%20.00%57.50%El Dorado County, California
Fresno100.00%100.00%99.73%99.93%Fresno County, California
Glenn100.00%100.00%20.00%10.30%Glenn County, California
Humboldt99.71%100.00%65.59%0.00%Humboldt County, California
Imperial100.00%100.00%0.00%0.00%Imperial County, California
Inyo100.00%100.00%3.52%6.01%Inyo County, California
Kern100.00%100.00%77.68%77.68%Kern County, California
Kings100.00%100.00%100.00%100.00%Kings County, California
Lake100.00%100.00%20.00%0.00%Lake County, California
Lassen100.00%100.00%54.29%62.12%Lassen County, California
Los Angeles100.00%100.00%87.36%87.92%Los Angeles County, California
Madera100.00%100.00%99.15%99.79%Madera County, California
Marin100.00%100.00%1.77%0.00%Marin County, California
Mariposa100.00%100.00%100.00%100.00%Mariposa County, California
Mendocino100.00%100.00%20.00%0.00%Mendocino County, California
Merced100.00%100.00%100.00%100.00%Merced County, California
Modoc100.00%100.00%0.00%0.00%Modoc County, California
Mono100.00%100.00%0.76%27.62%Mono County, California
Monterey100.00%100.00%100.00%56.86%Monterey County, California
Napa100.00%100.00%20.00%0.05%Napa County, California
Nevada100.00%100.00%20.00%44.97%Nevada County, California
Orange100.00%100.00%75.39%75.55%Orange County, California
Placer100.00%100.00%20.00%48.83%Placer County, California
Plumas100.00%100.00%46.02%33.81%Plumas County, California
Riverside98.96%100.00%0.33%0.33%Riverside County, California
Sacramento100.00%100.00%20.86%77.76%Sacramento County, California
San Benito100.00%100.00%100.00%86.71%San Benito County, California
San Bernardino90.09%100.00%0.57%0.57%San Bernardino County, California
San Diego100.00%100.00%0.00%0.00%San Diego County, California
San Francisco100.00%100.00%96.94%0.00%San Francisco County, California
San Joaquin100.00%100.00%67.67%99.81%San Joaquin County, California
San Luis Obispo100.00%100.00%100.00%99.97%San Luis Obispo County, California
San Mateo100.00%100.00%100.00%0.00%San Mateo County, California
Santa Barbara100.00%100.00%100.00%100.00%Santa Barbara County, California
Santa Clara100.00%100.00%100.00%24.67%Santa Clara County, California
Santa Cruz100.00%100.00%100.00%0.00%Santa Cruz County, California
Shasta100.00%100.00%31.95%5.76%Shasta County, California
Sierra100.00%100.00%28.16%31.33%Sierra County, California
Siskiyou99.80%100.00%13.87%0.00%Siskiyou County, California
Solano100.00%100.00%20.37%7.37%Solano County, California
Sonoma100.00%100.00%19.66%0.00%Sonoma County, California
Stanislaus100.00%100.00%86.22%100.00%Stanislaus County, California
Sutter100.00%100.00%20.00%75.00%Sutter County, California
Tehama100.00%100.00%20.00%0.78%Tehama County, California
Trinity100.00%100.00%70.93%0.00%Trinity County, California
Tulare100.00%100.00%100.00%100.00%Tulare County, California
Tuolumne100.00%100.00%61.92%98.34%Tuolumne County, California
Ventura100.00%100.00%100.00%100.00%Ventura County, California
Yolo100.00%100.00%20.00%67.84%Yolo County, California
Yuba100.00%100.00%20.00%74.84%Yuba County, California

Showing percentage of area experiencing exceptional drought for all California counties in January 2015. Source: US Drought Monitor.

Historical comparisons put the current drought levels in California into perspective and reveal exactly how extraordinary high and widespread they are:

  • In many counties, the areas experiencing drought in January of this year were more than twice as large as the average for that month has been in the past 10 years.
  • The exceptional levels of drought of this year are truly exceptional compared to the averages: 42 of the 58 counties had not experienced any exceptional drought levels (in the past 10 years) until this year; many of these counties now have to deal with it throughout all of its territory.
  • Exactly one county (Del Norte) had to deal with drought in a minority of its area; 53 out of 58 counties experienced levels of drought in 100% of its area - those areas are home to a combined 33.7 million people.

Drought in January 2015 compared to 10-year and 5-year averages for January

Showing percentage of area experiencing drought for all California counties. Use the filters to find a specific county or compare per region. Source: US Drought Monitor.

Exceptional drought in January 2015 compared to 10-year and 5-year averages for January

Showing percentage of area experiencing exceptional drought for all California counties. Use the filters to find a specific county or compare per region. Source: US Drought Monitor.

Counties with higher populations living below the poverty line have experienced more widespread droughts in the last 5 year (January)

Showing the 5-year average (2010-2014) percentage of area that experienced drought in January and the percentage of the county population that lives below the poverty line. Sources: US Drought Monitor and US Census Bureau.

Water Consumption

Three quarter of California's counties saw a dramatic increase in their levels of "exceptional drought" in January 2015 (compared to a 10-year average). Most of these counties also have relatively high levels of per capita public water consumption. 

Water consumption and areas experiencing exceptional drought

Bubble size shows public water consumption per capita in gallons/day. Bubble color shows the level of growth of the percentage of exceptional drought experienced January 2015 (as compared to the 10-year average). Sources: US Drought Monitor and US Geological Survey.

Water consumption by public and irrigation sector in Mgal/day

Showing 20 counties with highest amount of total water consumption in Mgal/day. Mgal = million gallons. Source: US Geological Survey.

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