Tribal Nations
Drought is a challenge most tribal nations face. Even small changes in the timing or amount of precipitation can induce drought conditions that negatively impact tribal communities, traditions, ecosystems, and economies.
The U.S. Drought Monitor depicts the location and intensity of drought across the country. The map uses 5 classifications: Abnormally Dry (D0), showing areas that may be going into or are coming out of drought, and four levels of drought (D1–D4).
This map shows U.S. Drought Monitor drought designations alongside tribal nation boundaries, according to U.S. Census Bureau legal boundary data.
This map shows precipitation for the past 30 days as a percentage of the historical average (1991–2020) for the same time period. Green/blue shades indicate above-normal precipitation, while brown shades indicate below-normal precipitation.
This map shows SNODAS snow water equivalent (SWE, the amount of liquid water contained within snowpack) for the past two days, as a percentage of the 2004–2021 average. The SNOw Data Assimilation System (SNODAS) is a modeling and data assimilation system developed by NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) to provide the best possible estimates of snow cover and associated parameters to support hydrologic modeling and analysis.
This NASA SPoRT-LIS soil moisture map shows the moisture content of the top 100 cm of soil compared to historical conditions (1981–2013), based on the Noah unified land surface model. Red and orange hues indicate drier soils, while greens and blues indicate greater soil moisture.
This map shows active large wildfires from the National Interagency Fire Center (NIFC) Incident Management Situation Reports, alongside current drought conditions from the U.S. Drought Monitor.
Note: This map only includes ongoing "large" wildland fires. It does not include prescribed burns, smaller fires, or other fires not included in NIFC's situation reports. View the latest situation report for more information.
A drought index combines multiple drought indicators (e.g., precipitation, temperature, soil moisture) to depict drought conditions. For some products, like the U.S. Drought Monitor, authors combine their analysis of drought indicators with input from local observers. Other drought indices, like the Standardized Precipitation Index (SPI), use an objective calculation to describe the severity, location, timing, and/or duration of drought.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MoreSoil moisture plays an important role in drought and flood forecasting, agricultural monitoring, forest fire prediction, water supply management, and other natural resource activities. Soil moisture observations can forewarn of impending drought or flood conditions before other more standard indicators are triggered.
Learn MoreFlash drought is the rapid onset or intensification of drought. Unlike slow-evolving drought, which is caused by a decline in precipitation, flash drought occurs when low precipitation is accompanied by abnormally high temperatures, high winds, and/or changes in radiation. These sometimes-rapid changes can quickly raise evapotranspiration rates and remove available water from the landscape.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought can result in reduced growth rates, increased stress on vegetation, and alterations or transformations to the plant community and/or the entire ecosystem. During periods of drought, plants increase their demand for water through increased evapotranspiration and longer growing seasons.
Learn MoreExtreme weather events can interact or cascade—where one disaster event triggers or changes the probability of another event. For example, drought conditions can increase the probability of large-scale wildfires, and droughts are often accompanied by extreme heat. By including drought in multi-hazard planning, a community can consolidate its resources and develop coordinated responses before a disaster.
Learn MoreDuring drought conditions, fuels for wildfire, such as grasses and trees, can dry out and become more flammable. Drought can also increase the probability of ignition and the rate at which fire spreads. Temperature, soil moisture, humidity, wind speed, and fuel availability (vegetation) are all factors that interact to influence the frequency of large wildfires.
Learn MoreU.S. Drought Monitor
D0 - Abnormally Dry
Abnormally Dry (D0) indicates a region that is going into or coming out of drought, according to the U.S. Drought Monitor. View typical impacts by state.
D1 – Moderate Drought
Moderate Drought (D1) is the first of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D2 – Severe Drought
Severe Drought (D2) is the second of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D3 – Extreme Drought
Extreme Drought (D3) is the third of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D4 – Exceptional Drought
Exceptional Drought (D4) is the most intense drought category, according to the U.S. Drought Monitor. View typical impacts by state.
Percent of Normal Precipitation (%)
<25% of Normal
Precipitation was only 0% to 25% of the historical average for this location, compared to the same date range from 1991–2020.
25%–50% of Normal
Precipitation was 25% to 50% of the historical average for this location, compared to the same date range from 1991–2020.
50%–75% of Normal
Precipitation was 50% to 75% of the historical average for this location, compared to the same date range from 1991–2020.
75%–100% of Normal
Precipitation was 75% to 100% of the historical average for this location, compared to the same date range from 1991–2020.
100%–150% of Normal
Precipitation was 100% to 150% of the historical average for this location, compared to the same date range from 1991–2020.
150%–200% of Normal
Precipitation was 150% to 200% of the historical average for this location, compared to the same date range from 1991–2020.
200%–300% of Normal
Precipitation was 200% to 300% of the historical average for this location, compared to the same date range from 1991–2020.
>300% of Normal
Precipitation was greater than 300% of the historical average for this location, compared to the same date range from 1991–2020.
SWE Percent of 2004–2021 Average
Trace or No Snow
Current snow water equivalent (SWE) is less than 0.01% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
0.01%–5% of Average SWE
Current snow water equivalent (SWE) is between 0.01%–5% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
5%–25% of Average SWE
Current snow water equivalent (SWE) is between 5%–25% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
25%–50% of Average SWE
Current snow water equivalent (SWE) is between 25%–50% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
50%–70% of Average SWE
Current snow water equivalent (SWE) is between 50%–70% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
70%–90% of Average SWE
Current snow water equivalent (SWE) is between 70%–90% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
90%–110% of Average SWE
Current snow water equivalent (SWE) is between 90%–110% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
110%–130% of Average SWE
Current snow water equivalent (SWE) is between 110%–130% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
130%–150% of Average SWE
Current snow water equivalent (SWE) is between 130%–150% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
150%–200% of Average SWE
Current snow water equivalent (SWE) is between 150%–200% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
200%–400% of Average SWE
Current snow water equivalent (SWE) is between 200%–400% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
400%–800% of Average SWE
Current snow water equivalent (SWE) is between 400%–800% of the average SWE value for this two-day period, compared to historical conditions from 2004–2021.
0–100 cm Soil Moisture Percentile
0–2nd Percentile
Soil moisture at 0–100cm depth is in the bottom 2% (0–2nd percentile) of historical measurements for this day of the year. Learn more.
2nd–5th Percentile
Soil moisture at 0–100cm depth falls between the 2nd to 5th percentile of historical measurements for this day of the year. Learn more.
5th–10th Percentile
Soil moisture at 0–100cm depth falls between the 5th to 10th percentile of historical measurements for this day of the year. Learn more.
10th–20th Percentile
Soil moisture at 0–100cm depth falls between the 10th to 20th percentile of historical measurements for this day of the year. Learn more.
20th–30th Percentile
Soil moisture at 0–100cm depth falls between the 20th to 30th percentile of historical measurements for this day of the year. Learn more.
30th–70th Percentile
Soil moisture at 0–100cm depth falls between the 30th to 70th percentile of historical measurements for this day of the year. Learn more.
70th–80th Percentile
Soil moisture at 0–100cm depth falls between the 70th to 80th percentile of historical measurements for this day of the year. Learn more.
80th–90th Percentile
Soil moisture at 0–100cm depth falls between the 80th to 90th percentile of historical measurements for this day of the year. Learn more.
90th–95th Percentile
Soil moisture at 0–100cm depth falls between the 90th to 95th percentile of historical measurements for this day of the year. Learn more.
95th–98th Percentile
Soil moisture at 0–100cm depth falls between the 95th to 98th percentile of historical measurements for this day of the year. Learn more.
98th–100th Percentile
Soil moisture at 0–100cm depth is in the top 2% (98th to 100th percentile) of historical measurements for this day of the year. Learn more.
Active Large Wildfires
Large Fire
The National Interagency Coordination Center classifies "large" wildland fires as 100 acres or larger in timber and slash fuel models; 300 acres or larger in grass or brush fuel models; or when a Complex, Type 1, or Type 2 Incident Management Team is assigned.
U.S. Drought Monitor
D0 - Abnormally Dry
Abnormally Dry (D0) indicates a region that is going into or coming out of drought, according to the U.S. Drought Monitor. View typical impacts by state.
D1 – Moderate Drought
Moderate Drought (D1) is the first of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D2 – Severe Drought
Severe Drought (D2) is the second of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D3 – Extreme Drought
Extreme Drought (D3) is the third of four drought categories (D1–D4), according to the U.S. Drought Monitor. View typical impacts by state.
D4 – Exceptional Drought
Exceptional Drought (D4) is the most intense drought category, according to the U.S. Drought Monitor. View typical impacts by state.
Tribal Nations
The U.S. Drought Monitor depicts the location and intensity of drought across the country. The map uses 5 classifications: Abnormally Dry (D0), showing areas that may be going into or are coming out of drought, and four levels of drought (D1–D4).
This map shows U.S. Drought Monitor drought designations alongside tribal nation boundaries, according to U.S. Census Bureau legal boundary data.
This map shows precipitation for the past 30 days as a percentage of the historical average (1991–2020) for the same time period. Green/blue shades indicate above-normal precipitation, while brown shades indicate below-normal precipitation.
This map shows SNODAS snow water equivalent (SWE, the amount of liquid water contained within snowpack) for the past two days, as a percentage of the 2004–2021 average. The SNOw Data Assimilation System (SNODAS) is a modeling and data assimilation system developed by NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) to provide the best possible estimates of snow cover and associated parameters to support hydrologic modeling and analysis.
This NASA SPoRT-LIS soil moisture map shows the moisture content of the top 100 cm of soil compared to historical conditions (1981–2013), based on the Noah unified land surface model. Red and orange hues indicate drier soils, while greens and blues indicate greater soil moisture.
This map shows active large wildfires from the National Interagency Fire Center (NIFC) Incident Management Situation Reports, alongside current drought conditions from the U.S. Drought Monitor.
Note: This map only includes ongoing "large" wildland fires. It does not include prescribed burns, smaller fires, or other fires not included in NIFC's situation reports. View the latest situation report for more information.
The U.S. Drought Monitor map is updated weekly on Thursday mornings, with data valid through the previous Tuesday at 7 am Eastern.
Precipitation data are updated daily, with a delay of 3 to 4 days to allow for data collection and quality control.
SNODAS data are updated daily.
This map updates daily with data from NASA's Short-term Prediction and Transition Center – Land Information System (SPoRT-LIS).
NIFC updates active large fire data daily or weekly, depending on the nation's National Preparedness Level. Learn more.
A drought index combines multiple drought indicators (e.g., precipitation, temperature, soil moisture) to depict drought conditions. For some products, like the U.S. Drought Monitor, authors combine their analysis of drought indicators with input from local observers. Other drought indices, like the Standardized Precipitation Index (SPI), use an objective calculation to describe the severity, location, timing, and/or duration of drought.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MoreSoil moisture plays an important role in drought and flood forecasting, agricultural monitoring, forest fire prediction, water supply management, and other natural resource activities. Soil moisture observations can forewarn of impending drought or flood conditions before other more standard indicators are triggered.
Learn MoreFlash drought is the rapid onset or intensification of drought. Unlike slow-evolving drought, which is caused by a decline in precipitation, flash drought occurs when low precipitation is accompanied by abnormally high temperatures, high winds, and/or changes in radiation. These sometimes-rapid changes can quickly raise evapotranspiration rates and remove available water from the landscape.
Learn MoreDrought can reduce the water availability and water quality necessary for productive farms, ranches, and grazing lands, resulting in significant negative direct and indirect economic impacts to the agricultural sector. Monitoring agricultural drought typically focuses on examining levels of precipitation, evaporative demand, soil moisture, and surface/groundwater quantity and quality.
Learn MoreDrought can result in reduced growth rates, increased stress on vegetation, and alterations or transformations to the plant community and/or the entire ecosystem. During periods of drought, plants increase their demand for water through increased evapotranspiration and longer growing seasons.
Learn MoreExtreme weather events can interact or cascade—where one disaster event triggers or changes the probability of another event. For example, drought conditions can increase the probability of large-scale wildfires, and droughts are often accompanied by extreme heat. By including drought in multi-hazard planning, a community can consolidate its resources and develop coordinated responses before a disaster.
Learn MoreDuring drought conditions, fuels for wildfire, such as grasses and trees, can dry out and become more flammable. Drought can also increase the probability of ignition and the rate at which fire spreads. Temperature, soil moisture, humidity, wind speed, and fuel availability (vegetation) are all factors that interact to influence the frequency of large wildfires.
Learn MoreCultural Impacts
Water holds a strong cultural significance for tribal nations and is often used in ceremonies. A lack of water impacts the survival of plants and animals, which hold additional cultural importance to tribal nations, as well as medicinal purposes. For example, during a drought, wild rice becomes more difficult to harvest and fewer berries are available. Warmer climates also allow invasive species to take hold (e.g., emerald ash borers are destroying ash trees, which are vital for basket making).
Ecosystem and Wildlife Impacts
The amount of vegetation that grows is often reduced during drought, impacting the amount of food available for wildlife on reservations. Reductions in wildlife can impact hunting and tribal-guided hunting opportunities. During drought, wildlife may also be more at risk for disease, and decreased water quality may lead to reduced fish populations, also crucial for subsistence.
Economic Impacts
Tribal nations are often engaged in farming, or lease their land to non-tribal farmers. Drought reduces the productivity of these lands, leading to significant economic losses for the tribal nations. Drought reduces the availability of the plants and animals available for hunting and gathering, undermining the economic resilience of tribal families.
Human Health Impacts
Drought is often accompanied by excessive heat, which increases stress on certain populations within tribal nations, including elders, children, and those without access to air conditioning. Existing economic stresses can also exacerbate the mental and physical stress of tribal community members during drought.
Drought Planning and Tribal Nations
Proactive drought planning and risk mitigation are essential for communities to prepare for and cope with the impacts of drought. Tribal nations often face unique challenges in the drought planning process, including limited funding and a shortage of reservation-specific data and monitoring stations.
Over the past few years, an increasing number of tribal nations have worked to better understand drought occurrence and its impacts on their lands and livelihoods, and develop drought preparedness and response plans to help minimize these impacts. However, despite this planning, many tribal resource managers have expressed frustration that this has not always translated into action on the ground. A major reason for this has been the lack of adequate funding for implementation of drought resilience activities and the competing priorities of other emergencies, such as flooding.
Another key challenge voiced by tribal resource managers is that there is limited reservation-specific monitoring and forecasting data available for use by tribal nations. In many cases, tribal resource managers have to rely on county-level data, which is not always reliable or reflective of drought conditions on the reservations.
There are many tribal nations taking action to better understand and prepare for drought conditions. Tribal drought activities include quarterly climate summaries and Drought Decision Dashboards for the Wind River Indian Reservation (see the case study below) and the Rosebud Sioux Tribe, in partnership with the High Plains Regional Climate Center, the Bureau of Indian Affairs, the Great Plains Tribal Water Alliance, and NIDIS. Additional regular activities include partnering on a monthly climate summary and outlook webinar series, delivered since 2012 for the North Central U.S.; and a webinar series with and for the New Mexico Pueblos, produced jointly with the Pueblo of Santa Ana Department of Natural Resources, NIDIS, the Quivira Coalition, USDA Southwest Climate Hub, and the New Mexico State Climate Office through the 2020 growing season.
Additional NIDIS support for tribal drought preparedness includes support for the Climate Assessment for the Southwest (CLIMAS, a NOAA RISA team) to collaborate with the Hopi Tribe Department of Natural Resources (HDNR) to develop a local drought information system. When the project started in 2010, there was a lack of weather and climate data that accurately and reliably captured local drought conditions on the Hopi Reservation. The purpose of the drought information system was to collect, analyze, and communicate local data and information that was relevant and appropriate for the Hopi Tribe’s needs in drought monitoring, response, and planning. The drought information system that was created was used to support informed decision making during drought and also for updating the Hopi drought mitigation and response plan. The process and methods used to engage the tribal community and co-create an effective and appropriate local drought information system were documented in this report and can be used to support the establishment of other local drought information systems.
These resources are critical to providing partners, including tribal nations, with the latest climate and drought conditions. There are also a growing number of technical and financial resources available for tribal nations to develop and implement drought-related plans.
Meet Crystal Stiles, NIDIS Tribal Engagement Coordinator
Have questions, feedback, or want to get involved? Contact Crystal Stiles, the NIDIS Tribal Engagement Coordinator, or sign up for the NIDIS Tribal Engagement email list.
Drought Monitoring and Planning in Action
Submit Drought Impacts
Report local drought-related conditions and impacts via the Condition Monitoring Observer Reports on Drought (CMOR-Drought).
Funding Opportunities
The Bureau of Indian Affairs, Federal Emergency Management Agency, Environmental Protection Agency, and other partners offer funding opportunities related to drought early warning research, planning, and preparedness.
Sign Up for Emails
Sign up for the NIDIS Tribal Engagement email list to receive updates on drought news, funding opportunities, and upcoming events and webinars for tribal nations across the United States.
Wind River Tribes Create New Drought Monitoring Tools
The Eastern Shoshone and Northern Arapaho Tribes of the Wind River Reservation in Wyoming have contended with periodic droughts, several of which have been particularly severe and impactful during the past two decades. After the drought of 2012 severely impacted these tribal nations’ water supply, the Tribal Water Engineer (TWE) wanted to find new ways to monitor conditions to help inform the Water Board’s decision making on whether or not to declare a drought during the spring. So, the TWE and their non-tribal partners created climate and drought summaries, which they produced on a quarterly basis to better track climate conditions, including drought. These tools have garnered interest from other tribal nations, which has resulted in subsequent partnerships to provide training on how to use climate information and produce climate summaries.
