Colorado River Basin
The U.S. Drought Monitor (USDM) is updated each Thursday to show the location and intensity of drought across the country. This map shows the drought conditions of the Colorado River Basin watershed, using a five-category system, from Abnormally Dry (D0) conditions to Exceptional Drought (D4). The USDM is a joint effort of the National Drought Mitigation Center, USDA, and NOAA. Learn more.
This map shows the departure from normal maximum temperature (°F) over the past 30 days, compared to usual conditions for the same time period averaged from 1991–2020.
This map uses the gridMET and PRISM temperature datasets. Temperature data are updated daily, with a delay of 3 to 4 days to allow for data collection and quality control. Learn more.
This map shows the percent of normal precipitation for the past 30 days, compared to the usual conditions for the same time period averaged from 1991–2020.
This map uses the gridMET and NLDAS precipitation datasets, and precipitation data are updated daily, with a delay of 3 to 4 days. Learn more.
- Short-term dryness slowing planting, growth of crops.
- Some lingering water deficits
- Pastures or crops not fully recovered
- Some damage to crops, pastures
- Some water shortages developing
- Voluntary water-use restrictions requested
- Crop or pasture loss likely
- Water shortages common
- Water restrictions imposed
- Major crop/pasture losses
- Widespread water shortages or restrictions
- Exceptional and widespread crop/pasture losses
- Shortages of water creating water emergencies
| Range | Map Hex Color |
|---|---|
| - -8 | #0404ff |
| -8 - -6 | #2166ac |
| -6 - -4 | #4393c3 |
| -4 - -3 | #92c5de |
| -3 - -1 | #d1e5f0 |
| -1 - 0 | #ffffff |
| Range | Map Hex Color |
|---|---|
| 0 - 1 | #ffffff |
| 1 - 3 | #fddbc7 |
| 3 - 4 | #f4a582 |
| 4 - 6 | #d6604d |
| 6 - 8 | #b2182b |
| 8 - | #800000 |
| Range | Map Hex Color |
|---|---|
| 0% - 25% | #8c510a |
| 25% - 50% | #bf812d |
| 50% - 75% | #dfc27d |
| 75% - 100% | #f6e8c3 |
| Range | Map Hex Color |
|---|---|
| 100% - 150% | #c7eae5 |
| 150% - 200% | #80cdc1 |
| 200% - 300% | #35978f |
| 300% - | #01665e |
| Value | Map Hex Color |
|---|---|
| D4 | #730000 |
| D3 | #E60000 |
| D2 | #FFAA00 |
| D1 | #FCD37F |
| D0 | #FFFF00 |
| Value | Map Hex Color |
|---|---|
| W0 | #AAFF55 |
| W1 | #01FFFF |
| W2 | #00AAFF |
| W3 | #0000FF |
| W4 | #0000AA |
The Multi-Indicator Drought Index (MIDI) looks at current drought conditions across the U.S. by integrating several key drought indices on precipitation and moisture into one objective, computer-generated map.
The Short-Term MIDI approximates drought impacts from changes in precipitation and moisture over a short-term timeframe (looking back up to 90 days), such as impacts to non-irrigated agriculture, topsoil moisture, and range and pasture conditions. Long-term droughts (lasting months to years) can have different impacts.
This experimental map is based on methodology from the NOAA National Weather Service’s Climate Prediction Center. Learn how this map is made.
| Value | Map Hex Color |
|---|---|
| D4 | #730000 |
| D3 | #E60000 |
| D2 | #FFAA00 |
| D1 | #FCD37F |
| D0 | #FFFF00 |
| Value | Map Hex Color |
|---|---|
| W0 | #AAFF55 |
| W1 | #01FFFF |
| W2 | #00AAFF |
| W3 | #0000FF |
| W4 | #0000AA |
The Multi-Indicator Drought Index (MIDI) looks at current drought conditions across the U.S. by integrating several key drought indices on precipitation and moisture into one objective, computer-generated map.
The Long-Term MIDI approximates drought impacts from changes in precipitation and moisture over a long-term timeframe (up to 5 years), such as impacts to irrigated agriculture, groundwater, and reservoir levels. Long-term drought conditions can also increase wildfire intensity and severity.
This experimental map is based on methodology from the NOAA National Weather Service’s Climate Prediction Center. Learn how this map is made.
The USDA's National Agricultural Statistics Service (NASS) conducts hundreds of surveys every year and prepares reports covering virtually every aspect of U.S. agriculture, including agricultural commodities statistics for crops and livestock. This map displays crops and livestock by county alongside the current U.S. Drought Monitor. Learn more.
Crop Production (Acres)
Crop Production (Acres)
Crop Production (Acres)
Livestock Count
Livestock Count
| Value | Map Hex Color |
|---|---|
| D0 - Abnormally Dry | #ffff00 |
| D1 - Moderate Drought | #ffcc99 |
| D2 - Severe Drought | #ff6600 |
| D3 - Extreme Drought | #ff0000 |
| D4 - Exceptional Drought | #660000 |
The U.S. Geological Survey (USGS) produces maps of real-time streamflow conditions compared to historical conditions. The map depicts streamflow conditions as computed at USGS streamgages. The colors represent real-time streamflow compared to percentiles of historical daily streamflow for the day of the year. Learn more.
The National Weather Service's Climate Prediction Center (CPC) produces precipitation outlooks for the U.S., including 6-10 day, 8-14 day, monthly, and seasonal outlooks. This 1-month outlook depicts whether there is a greater chance for above-normal or below-normal precipitation conditions over the next month. Learn more.
| Value | Map Hex Color |
|---|---|
| Low | #ff0000 |
| Much Below Normal | #b12121 |
| Below Normal | #ffa400 |
| Normal | #00ff00 |
| Above Normal | #40dfd0 |
| Much Above Normal | #0000ff |
| High | #000000 |
| Not Ranked | #FFFFFF |
| Value | Map Hex Color |
|---|---|
| D0 | #ffff00 |
| D1 | #ffcc99 |
| D2 | #ff6600 |
| D3 | #ff0000 |
| D4 | #660000 |
| Range | Map Hex Color |
|---|---|
| 33% - 40% | #f0d493 |
| 40% - 50% | #d8a750 |
| 50% - 60% | #bb6d33 |
| 60% - 70% | #9b5031 |
| 70% - 80% | #934639 |
| 80% - 90% | #804000 |
| 90% - 100% | #4f2f2f |
| Range | Map Hex Color |
|---|---|
| 33% - 40% | #b3d9ab |
| 40% - 50% | #94cd7e |
| 50% - 60% | #48ae38 |
| 60% - 70% | #3a7b5f |
| 70% - 80% | #008e40 |
| 80% - 90% | #28553d |
| 90% - 100% | #285517 |
Historical Conditions for the Colorado River Basin
The U.S. Drought Monitor (USDM) is a national map released every Thursday, showing parts of the U.S. that are in drought. The USDM relies on drought experts to synthesize the best available data and work with local observers to interpret the information. The USDM also incorporates ground truthing and information about how drought is affecting people, via a network of more than 450 observers across the country, including state climatologists, National Weather Service staff, Extension agents, and hydrologists. Learn more.
The Standardized Precipitation Index (SPI) is an index to characterize meteorological drought on a range of timescales, ranging from 1 to 72 months. The SPI is the number of standard deviations that observed cumulative precipitation deviates from the climatological average. NOAA's National Centers for Environmental Information produce the 9-month SPI values below on a monthly basis, going back to 1895. Learn more.
Tree-rings are used to extend the instrumental record of drought to over 2000 years. The Living Blended Drought Product (LBDP) is a recalibrated data series of June-July-August Palmer Modified Drought Index (PMDI) values in the lower 48 U.S. states. This dataset blends tree-ring reconstructions and instrumental data to estimate the average summer PMDI values, which extend over 2000 years in some parts of the U.S. Learn more.
Drought in the Colorado River Basin
Reliance on Colorado River Water Resources
The Colorado River provides water to almost 40 million people in two countries, seven states, 29 federally recognized Indian tribes, and 4 million acres of farmland. According to a University of Arizona study, the Colorado River supports $1.4 trillion in annual economic activity—equivalent to 1/12th of total U.S. gross domestic product—and 16 million jobs in Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Since 2000, historically dry conditions have added stress to the Colorado River’s already over-allocated water resources.
Story Map: Drought in the Colorado River Basin
Since 2000, the Colorado River basin has been experiencing a historic, extended drought that has impacted regional water supply and other resources, such as hydropower, recreation, and ecological goods and services services.
Learn more about the current 16-year drought and its effects on the Colorado River basin through this story map, which was created by the U.S. Geological Survey and the Bureau of Reclamation.
Colorado Basin River Forecast Center
View river, snow, and reservoir conditions; forecasts of temperature, precipitation, water supply and peak flows; soil moisture conditions and other data, maps, and tools for the Colorado River through the National Weather Service Colorado Basin River Forecast Center (CBRFC).
The CBRFC is responsible for monitoring and forecasting climate conditions for the entire Colorado River basin and the Great Basin, covering an area of 303,450 square miles.
Colorado River Interim Guidelines and the Drought Contingency Plan
Since 2008, Lake Mead and Lake Powell have been operated in accordance with the 2007 Record of Decision for the Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead. The Guidelines define operating procedures during drought and low reservoir conditions to minimize shortages in the Lower Colorado basin and avoid the risk of curtailment in the Upper Colorado basin. These Guidelines remain in effect through 2025. In advance of negotiating new Guidelines, in 2020 the U.S. Bureau of Reclamation issued a report on an assessment of effectiveness of the Guidelines. A key conclusion of the report was that “increasing severity of the drought necessitated additional action to reduce the risk of reaching critically low elevations in Lakes Powell and Mead.”
In addition, to reduce the risk of Lake Powell and Lake Mead declining to critically low levels, in December 2017, the U.S. Department of the Interior called on the seven Colorado River basin states to put drought contingency plans in place before the end of 2018. Congress approved the plan submitted by the states of Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming as the Colorado River Drought Contingency Plan Authorization Act on April 16, 2019.
