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Frequently Asked Questions

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What is the National Risk Index?

The National Risk Index is a dataset and online tool that can be used to help illustrate the United States communities most at risk for 18 hazard types: Avalanche, Coastal Flooding, Cold Wave, Drought, Earthquake, Hail, Heat Wave, Hurricane, Ice Storm, Landslide, Lightning, Riverine Flooding, Strong Wind, Tornado, Tsunami, Volcanic Activity, Wildfire, and Winter Weather.

It was designed and built by FEMA in close collaboration with various stakeholders and partners in academia; local, state, and federal governments; and private industry. The Risk Index leverages available source data for natural hazard and community risk factors to develop a baseline relative risk measurement for each United States county and Census tract. The National Risk Index is intended to help users better understand the natural hazard risk of their communities.

FEMA has recently published a series of tutorial videos highlighting the main features of the National Risk Index and explains the methodologies behind our interpretation of risk data. Click here to view the list of videos.

Who is the National Risk Index for?

The National Risk Index is intended for planners and emergency managers at the local, regional, state, and federal levels, as well as individual residents and other decision makers. In addition to traditional emergency management and hazard mitigation uses, the National Risk Index can also inform resource allocation, individual and community-level hazard preparedness, and support the adoption of enhanced building codes and standards. It is made publicly available for any interested members of the general public seeking to better understand the risk from natural hazards in their community.

Learn more about how the National Risk Index can help

Which parts of the United States are included in the National Risk Index?

The National Risk Index provides Risk Index scores and ratings for counties and Census tracts for all 50 states and the District of Columbia. Expected Annual Loss scores and ratings are available for all 50 states, the District of Columbia, American Samoa, Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands. Social Vulnerability scores and ratings are available for all 50 states, the District of Columbia, and Puerto Rico. Community Resilience scores and ratings are available for all 50 states and the District of Columbia. As data becomes more available, we will work to update the National Risk Index to include the remaining indices for Tribal Nations and U.S. Territories.

For Tribal Nations, the National Risk Index has data resources available to help identify the spatial relationships between tribal land area representation and the National Risk Index data.

FEMA continues to work with our partners on developing data to support natural hazard risk assessment. For more information or to provide a data source for consideration, please email FEMA-NRI@fema.dhs.gov.

How were natural hazards selected for the National Risk Index?

State mitigation plans from all 50 states were reviewed, and the most common natural hazard types profiled in all plans were identified. If a hazard type was profiled by at least 25 states, then it was included in the National Risk Index. Regionally significant hazards (e.g., hurricanes, tsunamis, or volcanic activity) were also included.

The National Risk Index includes 18 hazard types:

  • Avalanche
  • Coastal Flooding
  • Cold Wave
  • Drought
  • Earthquake
  • Hail
  • Heat Wave
  • Hurricane
  • Ice Storm
  • Landslide
  • Lightning
  • Riverine Flooding
  • Strong Wind
  • Tornado
  • Tsunami
  • Volcanic Activity
  • Wildfire
  • Winter Weather

Manmade hazards, such as dam and levee failure, are profiled by some state mitigation plans. However, the data required to calculate Expected Annual Loss, a component of the National Risk Index, for such hazards are not nationally or publicly available.

Hazard mitigation plans for Tribal Nations and U.S. Territories were not reviewed due to their limited availability, and as a result, they were not included in the hazard analysis.

Who provided source data for the National Risk Index?

Source data for the National Risk Index were provided by many different organizations.

  • Data for Expected Annual Loss were provided by a mix of federal and state agencies, academia, and other research institutions. The types of data used vary across hazard types, as do the periods of record. For some hazard types, multiple data sources were used, while others rely on only a single dataset. Visit the natural hazard-specific pages for more details.
  • The Social Vulnerability component of the National Risk Index is supported by the Social Vulnerability Index (SVI) and Community Resilience is supported by the Baseline Resilience Indicators for Communities (BRIC). The SVI is provided by the Centers for Disease Control and Prevention (CDC)/Agency for Toxic Substances and Disease Registry (ATSDR), Geospatial Research, Analysis, and Services Program (GRASP). The BRIC is provided by the Hazards and Vulnerability Research Institute (HVRI) at the University of South Carolina.

What types of data does the National Risk Index use to estimate annualized frequency?

The National Risk Index uses the best available national datasets for each hazard type to estimate their respective annualized frequencies. For most hazard types, the spatial source data used to derive annualized frequencies provide an historic record of hazard events with details regarding their location and extent. In these cases, annualized frequency for a given community is determined by the number of historic events divided by the period of record.

For other hazards, such as Earthquake, Wildfire, and Coastal Flooding, the best available spatial source data are probabilistic (rather than historic) and provide location-specific estimates regarding the probability of a given hazard type occurring there within a typical year. Annualized frequency estimates derived from probabilistic data are generally determined by intersecting the spatial source data layer with boundaries from the U.S. Census Bureau's 2021 TIGER/Line Shapefiles and Geodatabases and calculating an area-weighted average.

For more details regarding our data and methods, please see the National Risk Index Technical Documentation.

Where does the National Risk Index obtain its loss data from historic events?

The National Risk Index obtains loss data for historic hazard events from the Arizona State University (ASU) Center for Emergency Management and Homeland Security’s SHELDUSTM database.

ASU provides summary SHELDUS™ data that aggregates property damage, crop losses, injuries, and fatalities due to a peril or hazard by month, year, and county since 1960. FEMA uses unaggregated data collected at the hazard occurrence level for the National Risk Index.

While SHELDUS™ represents the best available national dataset on building, population, and agriculture losses, much of its data was obtained from NOAA Storm Events Database and the NOAA Storm Data Publications. To account for any underreporting, the National Risk Index views SHELDUS™ data as providing a baseline or lower-bound estimate of losses due to hazard events when incorporating it into our assessments.

For more information about SHELDUS™, please visit their website, and National Risk Index Technical Documentation which further details the National Risk Index’s use of SHELDUS™ data.

What are the National Risk Index scores and ratings? How are they calculated?

The National Risk Index provides relative Risk Index scores and ratings based on data for Expected Annual Loss due to natural hazards, Social Vulnerability, and Community Resilience. For the Risk Index and Expected Annual Loss, ratings can be viewed as a composite score for all hazards or individually for each of the 18 hazard types.

Risk Index and Expected Annual Loss values are calculated using values from the following equations:

Risk = Expected Annual Loss × ƒ(Social Vulnerability ∕ Community Resilience)

where Community Risk Factor = ƒ(Social Vulnerability ∕ Community Resilience)

Expected Annual Loss = Exposure × Annualized Frequency × Historical Loss Ratio

As described in the Risk equation above, Risk Index values are determined by multiplying Expected Annual Loss by the Community Risk Factor. The Community Risk Factor is a scaling factor determined by social vulnerability and community resilience. The function f() is defined such that higher social vulnerability and lower community resilience, relative to all other communities at the same level (county or Census tract), result in higher Risk Index values for a given Expected Annual Loss.

The National Risk Index provides three different types of results for the four indices: Value, Score, and Rating.

Value represents the community’s average economic loss from natural hazards each year in US dollars ($). It is calculated for both the Risk and Expected Annual Loss (EAL) indices. The EAL Value describes total expected monetary losses to property, agriculture, and population due to a given hazard, whereas the Risk Index Value scales the monetary losses to incorporate the impacts of social vulnerability and community resilience using the Community Risk Factor (CRF).

Scores represent a community’s ranking from 0 (lowest possible value) to 100 (highest possible value). It is set equal to the community’s percentile ranking among all other communities of the same enumeration unit (County or Census tract). For example, a County's Risk Index score and rating is relative to all other counties in the United States, and a Census tract's Risk Index score and rating is relative to all other Census tracts in the United States.

The rating is a qualitative categorization that describes the community in comparison to all other communities at the same level, ranging from “Very Low” to “Very High.” The methodology used to determine ratings varies across components.

To determine Risk and Expected Annual Loss ratings, a methodology known as k-means clustering or natural breaks is applied to each value. This approach divides all communities into five groups such that the communities within each group are as similar as possible (minimized variance) while the groups are as different as possible (maximized variance).

A cubed root transformation is applied to both Risk and Expected Annual Loss values before k-means clustering. Without the transformation, these values are heavily skewed by an extreme range of population and building value densities between urban and rural communities. By applying a cube root transformation, the National Risk Index controls for this characteristic and provides ratings with greater differentiation and usefulness.

Ratings for Social Vulnerability and Community Resilience on the other hand have specific numerical boundaries based on their national percentiles. These are consistent across all hazards and are divided into the quintiles described below:

  • Very High: 80th to 100th percentiles
  • Relatively High: 60th to 80th percentiles
  • Relatively Moderate: 40th to 60th percentiles
  • Relatively Low: 20th to 40th percentiles
  • Very Low: 0th to 20th percentiles

For comprehensive details about National Risk Index values, scores and ratings, see the National Risk Index Technical Documentation.

How can I view scores and ratings for the National Risk Index and its individual components?

Use the National Risk Index Map to view color-coded map layers that visualize ratings and select a county or Census tract on the map to view ratings, scores, and other details. The map's reporting feature enables you to generate printable reports containing National Risk Index scores and ratings for one or more communities. For help with using the National Risk Index Map or reporting feature, review the User Guide.

Users can also access several National Risk Index data resources, including downloadable datasets.

How do I find the highest risk hazard type in a county or Census tract?

Find the county or Census tract of interest using the National Risk Index Map and select it to open the information panel. In the Risk Index view, review the Hazard Type Risk Ratings section. You could also create a printable report for the community using the National Risk Index Map's reporting feature. Identify the hazard type with the highest Risk and Expected Annual Loss values—this is the community's highest risk hazard type. This measure should not be interpreted as the hazard type that is most likely to occur. Rather, it represents the hazard type with the highest potential for negative impacts. Note: the percentiles for each hazard type measure the community's national rank for that hazard type. You should not compare percentiles across hazards to determine which is higher risk.

For help with using the National Risk Index Map or its reporting feature, review the User Guide.

How can I compare the natural hazard risk ratings between multiple counties or census tracts?

Find the area of interest on the National Risk Index Map. Use the reporting feature to select the counties or Census tracts you want to compare and create a Community Risk Comparison Report. The communities are sorted by Risk Index scores (high-to-low), and the community listed first with the highest Risk Index score has the highest natural hazard risk of those selected. The resulting table should not be interpreted as a comparison of which county or Census tract has the highest likelihood of a hazard occurring. Rather, the data represent which county or tract has the highest potential for negative impacts from a given hazard type.

For help with using the National Risk Index Map or its reporting feature, review the User Guide.

How can a county have a high Risk Index rating, but its Census tracts have low Risk Index ratings?

Census tracts are subdivisions of counties based on a population criterion of approximately 4,000 people. The number of Census tracts in a county vary widely. Some rural counties have only one Census tract while urban counties may have hundreds or even thousands of Census tracts.

A community's Risk Index rating, for either a county or Census tract, describe its level of Risk relative to all other communities at the same level for a given hazard type. This means that a county's Risk Index rating is relative to all other counties in the United States, and a Census tract's Risk Index rating is relative to all other Census tracts in the United States.

Thus, it is possible for a county with a large number of Relatively Low or Very Low risk rated Census tracts to have a Relatively High or even Very High risk rating. Conversely, it is possible for a county with a few Relatively High or Very High risk rated Census tracts to have a Relatively Low or Very Low risk rating.

In the next year, is it possible for a community with a low Risk rating to experience more losses due to hazard impacts than a community with a high Risk rating?

Yes. Natural hazard occurrences can vary across time and location and year to year. If a hazard is possible in an area, even if that area has a low Risk Index Rating, a hazard can still occur and cause adverse impacts. Low risk includes more than just hazard frequency, including minimal exposure or low historic losses.

The purpose of the National Risk Index is not to predict the amount of damage communities will experience due to natural hazards within the next year. Our goal is to provide an assessment of relative natural hazard risk across communities, while understanding that natural hazards can cause local deviations from expected outcomes.

Is it possible for a community to have a high annualized frequency and a low Risk Index rating for the same hazard type?

Yes. Annualized frequency is only one of the three factors that determines Expected Annual Loss, which is the primary determinant of Risk. If the hazard events driving a community’s annualized frequency estimate occur in areas with little to no exposure, then the community’s Expected Annual Loss and Risk Index values will be low (for the hazard in question).

Alternatively, a community with a relatively high annualized frequency may have strong building codes designed to prevent damage from such regularly occurring hazards. This type of mitigation could result in a lower historic loss ratio which would, in turn, reduce Expected Annual Loss and Risk values for the community.

What is the difference between Social Vulnerability and Community Resilience?

Community resilience is the ability of a community to prepare for anticipated natural hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions. It emphasizes community networks, local knowledge, and the systems in place that can help a community absorb and bounce back after a disruption.

Social vulnerability is the susceptibility of social groups to the adverse impacts of natural hazards, including disproportionate death, injury, loss, or disruption of livelihood. It focuses on attributes that shape a population’s inherent sensitivity to hazard events.

While social vulnerability and community resilience are related concepts (i.e., a community with high social vulnerability might exhibit lower community resilience), they represent different aspects of a community's relationship with natural hazards. A community can be vulnerable in specific ways and yet have elements of resilience in other aspects, and both concepts play an important role in shaping hazard risk across communities and require different metrics for measuring natural hazard risk.

Why are some data missing for my county or Census tract?

All data supporting National Risk Index risk components were required to be nationwide in scope and able to be measured at the Census tract level. Hazard type data sources were also required to have location and time information. For some counties and Census tracts, data that met these requirements were simply not available.

The National Risk Index uses specific ratings to communicate if a community is missing data:

  • Not Applicable indicates there is no historical record in the National Risk Index source data for a hazard type and the hazard type is not geographically possible (i.e., Coastal Flooding in inland areas). These were rated in collaboration with subject matter experts most familiar with the hazard type and the source data. Therefore, there is no perceived probability of the hazard impacting a community.
  • Insufficient Data indicates that the community lacks data for one or more of the factors required to calculate Expected Annual Loss or Risk.
  • Data Unavailable indicates source data are not available for a National Risk Index component. This is specific to Social Vulnerability and Community Resilience only.
  • No Rating indicates that the community has an Expected Annual Loss value equal to zero. This will occur whenever a community has no building value, population, or agriculture value exposed to the hazard type, or the community has a calculated annualized frequency of zero for the hazard type.
  • No Expected Annual Losses indicates one of the Expected Annual Loss factors has a value of 0 and Expected Annual Loss cannot be calculated for a hazard type. If a community has No Expected Annual Loss for a hazard type, then the hazard type does not contribute to the composite Expected Annual Loss score for all 18 hazard types.

Why are Risk scores and ratings missing from the U.S. Territories?

At this time, only the Expected Annual Loss for 14 of the 18 hazards exist in terms of hazard data for the U.S. Territories, which are American Samoa, Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico and the U.S. Virgin Islands. Social Vulnerability data are currently only available for Puerto Rico. Due to the lack of data for Social Vulnerability (with the exception of Puerto Rico) and Community Resilience in the U.S. Territories, we are unable to calculate Risk scores and ratings for these areas.

FEMA continues to work with our partners on developing data to support natural hazard risk assessment. For more information or to provide a data source for consideration, please email FEMA-NRI@fema.dhs.gov.

Why does my county or Census tract, which is known for a natural hazard type, have a low Risk Index score for that hazard type?

Even if a community has well-known activity for a hazard type, the community's risk for that hazard type may be low because its people or assets are less vulnerable to the hazard type's impacts and/or more resilient when impacted. In terms of the National Risk Index, a community's Expected Annual Loss score for a hazard type may be high, but its Risk Index score may be low because it has lower Social Vulnerability and/or higher Community Resilience scores.

Also, the National Risk Index leverages the best available nationwide datasets. Nationwide datasets used as inputs for the National Risk Index are in many cases not as accurate as available local data. Users with access to local data for any National Risk Index risk factor should consider deferring to that data to calculate a more accurate risk measurement.

How does the National Risk Index handle Census tracts without population or building values?

The National Risk Index obtains its population and building valuation data from Hazus 6.0.

If Hazus 6.0 reports a building replacement cost value of $0 for a given Census tract, then its Exposure and Expected Annual Loss values for the building consequence type will be equal to $0 across all applicable hazards.

However, due to the nature of certain hazard types and their effects on people, population values of 0 are handled differently across hazard types. For more information, please see Section 5.3 of the National Risk Index Technical Documentation.

What types of consequences are factored into the National Risk Index? Are all types of consequences considered for each hazard type?

Natural hazard loss is represented by the Expected Annual Loss component of the National Risk Index. Expected Annual Loss is based on three consequence types: buildings, population, and agriculture.

Not all consequence types are considered for all hazard types. Building and population exposure are modeled for all hazard types except Drought, which only modeled agriculture exposure. Agriculture exposure was also modeled for Cold Wave, Hail, Heat Wave, Hurricane, Riverine Flooding, Strong Wind, Tornado, Wildfire, and Winter Weather.

What do the building values reported in Hazus 6.0 represent?

The building values derived from Hazus 6.0 represent the replacement cost value of structures with a given geographic area.

In the context of Hazus, the term “replacement value” refers to the estimated cost required to replace a building or structure with a similar one after it has been damaged or destroyed by a natural hazard. This value accounts for factors such as construction materials, labor costs, and other expenses necessary to rebuild the structure to its pre-disaster condition. For additional information, please see the Hazus Inventory Technical Manual.

What is the source of geographic/administrative boundaries in the National Risk Index?

The source of geographic/administrative boundaries used by the National Risk Index is the U.S. Census Bureau's 2021 TIGER/Line Shapefiles and Geodatabases.

For comprehensive details about how geographic/administrative boundaries are defined by the National Risk Index, see the National Risk Index Technical Documentation.

What is missing from the National Risk Index?

The National Risk Index is missing the following source data:

  • Landslide source data for Alaska, American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the U.S. Virgin Islands.
  • Lightning source data for Alaska, American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, Hawaii, Puerto Rico, and the U.S. Virgin Islands.
  • Tsunami source data for the Commonwealth of the Northern Mariana Islands.
  • Hail, Strong Wind, and Tornado source data for American Samoa, the Commonwealth of the Northern Mariana Islands, and Guam.
  • Drought source data for American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands.
  • Earthquake source data for American Samoa, the Commonwealth of the Northern Mariana Islands, and Guam; however, proxy Expected Annual Loss estimates were developed based on statistical models.
  • Wildfire source data for American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands.
  • Social Vulnerability source data for American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the U.S. Virgin Islands.
  • Community Resilience source data for American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands.

Are there comparable historic versions of the National Risk Index?

We have released three versions of the National Risk Index data to date, and those are available on our Data Archive page. The 2020 version is the first version we released. For comparing risk over time, we recommend using the Expected Annual Loss components, not the risk scores, as its methodology for calculating risk scores has changed over time. Additionally, with each version, we've made some methodological updates. These are detailed in our National Risk Index Data Version and Update Documentation. Unfortunately, only Expected Annual Loss values can be used to compare data between versions.

Is future risk incorporated into the National Risk Index?

Currently, the National Risk Index does not incorporate future risk data. There is a separate tool, the National Risk Index: Future Risk prototype, which compares each county's projected future natural hazard risk to today's risk, and to that of all other counties. This tool includes Projected Annual Loss and Projected Risk for Coastal Flooding, Drought, Heat Wave, Hurricane and Wildfire hazards. You can access this tool through the "Future Risk" button at the top of the NRI map.

What is the National Risk Index: Future Risk prototype, and how is it different from the National Risk Index?

The National Risk Index: Future Risk prototype is a separate tool from the National Risk Index. The NRI shows present-day risk ratings and Expected Annual Losses across 18 natural hazards and remains a comprehensive tool for risk assessment. The National Risk Index: Future Risk prototype is built from the NRI, and shows projected risk from five natural hazards in different future scenarios.

Does the National Risk Index account for uncertainty when assessing hazard risk across communities?

Although the current data release of the National Risk Index does not report specific metrics related to uncertainty (e.g., margins of error), the methods used to derive the National Risk index do account for uncertainty in a variety of ways.

For instance, when processing the spatial Tornado source data, we buffer the historic event features in our spatial source data to better represent the area where the event could possibly have occurred. Additionally, for hazards like Ice Storm and Landslide, we assign minimum annual frequencies to geographies without historic events, which could experience them in the future.

For more details regarding our data and methods, please see the National Risk Index Technical Documentation.

What are the limitations of the National Risk Index?

Please review the Disclaimer for an official statement on the National Risk Index's limitations.

Also, the National Risk Index and its scores, ratings, and methodology do not explicitly consider or account for:

  • Natural hazard forecasts.
  • Climate change and its projected impacts. *
  • Dependencies between hazard types or interrelated hazard types (e.g., Coastal Flooding and Hurricanes).
  • Secondary hazard types (e.g., ash fall from Volcanic Activity or flash flooding after Wildfire).
  • Previous, ongoing, or future natural hazard mitigation efforts.
  • Levees, dams, or other flood control structures. **
  • Manmade hazards. †
  • Historical, priority natural disaster response coordination.
  • A community's evacuation efficiency.
  • Changes in a community over time (e.g., a county having more farmland in the past than now).
  • Impacts to infrastructure.
  • Impacts to transportation.
  • Impacts to critical facilities (e.g., hospitals).
  • Supply chain impacts.

  • Economic damages from the disruption of business.

* To some extent, some of the listed aspects of natural hazard risk may be included in the source data used by the National Risk Index. Please refer to information by source data providers for more information on what is included in their datasets.

** Levees, dams, or other flood control structures are factored into the Coastal or Riverine Flooding hazards of the National Risk Index only if the manmade features are incorporated into the source datasets.

† The data required to calculate Expected Annual Loss for manmade hazards, such as dam and levee failure, are not nationally or publicly available. Also, such hazards should not be discussed separately from traditional, natural hazard risk assessment.

Can I use the National Risk Index and associated data for commercial purposes?

Yes, National Risk Index data could be used for commercial purposes assuming the limitations of the data are recognized, and it is acknowledged that data are provided “as-is” without warranty of any kind as described in the National Risk Index metadata. Please attribute any use of the National Risk Index and its associated data to the Federal Emergency Management Agency per the citation below. For more information, please visit our Disclaimer Page.

Preferred citation for the National Risk Index Technical Documentation:

Zuzak, C., E. Goodenough, C. Stanton, M. Mowrer, A. Sheehan, B. Roberts, P. McGuire, and J. Rozelle. 2023. National Risk Index Technical Documentation. Federal Emergency Management Agency, Washington, DC

Preferred citation for the National Risk Index Publication:

Zuzak, C., Mowrer, M., Goodenough, E. et al. The national risk index: establishing a nationwide baseline for natural hazard risk in the US. Nat Hazards 114, 2331-2355 (2022). https://doi.org/10.1007/s11069-022-05474-w

Preferred citation for the National Risk Index Data:

Federal Emergency Management Agency. (2023). FEMA National Risk Index Data v 1.19.0 [Dataset]. Department of Homeland Security. https://hazards.fema.gov/nri/data-resources

How can I use the National Risk Index to reduce my natural hazard risk?

There are many ways you can leverage the National Risk Index to better understand your natural hazard risk and use this understanding to reduce your risk. Visit the Take Action section of the website to learn how.

Can I calculate the National Risk Index on a state basis versus a county/Census tract basis?

Yes, this is possible, however discourage the calculation of the National Risk Index scores on a state level due to the variability of Social Vulnerability and Community Resilience within a state. To calculate the Expected Annual losses, simply aggregate Expected Annual Loss values within each geographic entity and follow our Risk Index score and rating methodologies described in Section 3.2 of the National Risk Index Technical Documentation.

Can I download National Risk Index data? What formats are available?

All National Risk Index data are free and available for download in spatial (GIS) format as geodatabases and shapefiles and table format (CSV). You can download complete National Risk Index datasets for all 50 states, the District of Columbia, American Samoa, Commonwealth of the Northern Mariana Islands, Guam, Puerto Rico, and the U.S. Virgin Islands in all formats. Individual state and territory datasets are available in table format only. Datasets are available at both the county and Census tract level. Once you download the data, you may use the data in your tool or software of preference.

National Risk Index GIS web layers and services are also available through the National Risk Index Group on FEMA's ArcGIS Online.

Please review the Disclaimer for an official statement on the National Risk Index's limitations.

When will the National Risk Index data be updated?

The National Risk Index Team continuously updates the National Risk Index as new data become available and improved methodologies are identified. FEMA has committed to providing regular updates to the National Risk Index and any questions about future releases should be directed to FEMA-NRI@fema.dhs.gov.

Learn more about the latest updates to the National Risk Index data and website

Why do I need another tool to prioritize areas of risk? How is the National Risk Index different?

The National Risk Index is different from other traditional models because it analyzes 18 natural hazard types, in addition to a community's social vulnerability and community resilience, to provide a more holistic view of risk. It is a great alternative for communities that do not have access to mapping services, since it uses authoritative data from a variety of contributors.

How does the National Risk Index align with historic FEMA funding? Have “high-risk areas” traditionally received the most funding?

Many decisions are made at a state level, influenced by funding availability, and have qualifying levels. The community resilience component (Baseline Resilience Indicators for Communities) includes the following information:

  • Mitigation spending: 10-year average per capita spending for mitigation projects.
  • Flood insurance coverage: Percentage of housing units covered by National Flood Insurance Program policies.
  • Disaster aid experience: The number of presidential disaster declarations divided by the number of loss-causing events.

Should I prioritize risk reduction funding directly based on the National Risk Index?

The National Risk Index is intended to inform risk-based decision making while increasing risk awareness. This tool can be one source of information to support risk reduction investments, but other information and tools (e.g., a benefit-cost analysis or local knowledge) should also be considered.

My community had a large-scale event recently but does not show up as “high risk.” Why not?

The National Risk Index identifies a community's risk to natural hazards. Community risk combines several factors, including the expected annual dollar loss related to building value, population or agriculture value due to a natural hazard; social vulnerability, representing the susceptibility of social groups to the adverse impacts of natural hazards; and community resilience, measuring the ability of a community to prepare for anticipated natural hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions.

With these factors, even if a community experiences a large-scale event, its risk may be relatively low overall if it has a highly resilient population, a relatively low overall frequency of hazards, etc.

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