About PlainHazard

Our Mission

We believe every American should have easy access to historical disaster data for the places they live, work, and consider moving to. PlainHazard exists because natural hazard information is scattered across multiple federal agencies, each with different formats, time ranges, and terminology. Finding out what disasters have affected a specific county should not require navigating three different government portals.

Our mission is to aggregate disaster declaration records, severe weather events, and risk index scores into a single, searchable resource, organized by state and county, so that homeowners, researchers, emergency planners, real estate professionals, and journalists can quickly assess the historical hazard profile of any location in the United States.

PlainHazard covers all 50 states, the District of Columbia, and US territories including Puerto Rico, Guam, and the US Virgin Islands. We preserve source figures in their labeled fields, distinguish PlainHazard aggregates and comparisons from agency figures, and never present our own calculations as a FEMA or NOAA rating.

Our Data Sources

PlainHazard draws from three official U.S. government data sources, each providing a different dimension of hazard information:

• FEMA OpenFEMA, Disaster Declarations Summaries v2
  The federal disaster declaration program dates to 1953, but PlainHazard's dataset covers all federally declared disasters from 1973 to the present, the earliest year with complete digitized OpenFEMA records, including major disaster declarations, emergency declarations, and fire management assistance declarations. Each record includes the disaster type, declaration date, and affected areas at the county level. fema.gov/openfema
• NOAA NCEI, Storm Events Database
  The National Centers for Environmental Information maintains records of severe weather events including thunderstorms, tornadoes, floods, hail, hurricanes, winter storms, and 50+ other event types. Our data covers 2015 through 2025 and includes event counts, fatalities, injuries, and property and crop damage estimates. ncei.noaa.gov/stormevents
• FEMA National Risk Index (NRI)
  A county-level dataset that quantifies risk for 18 natural hazard types using a composite score based on expected annual loss, social vulnerability, and community resilience. The NRI provides standardized risk ratings (Very Low to Very High) for hazards including avalanche, coastal flooding, drought, earthquake, hail, hurricane, tornado, wildfire, and more. hazards.fema.gov/nri

How We Process the Data

PlainHazard merges three federal datasets into a unified hazard profile for every US state and county. Each source is loaded separately and organized geographically using FIPS codes as the common key.

FEMA disaster declarations are aggregated from individual declaration records to state and county levels. We count total declarations by type (major disaster, emergency, fire management) and track the historical timeline of federal disaster responses for each geography.

NOAA storm events are aggregated by state, county, year, and event type. Property and crop damage figures are reported in nominal dollars as provided by NOAA. Fatality and injury counts include both direct and indirect causes as classified by the source. We parse the raw CSV bulk files published by NCEI, handling the varied event type codes and geographic identifiers across reporting years.

National Risk Index scores are loaded from FEMA's ArcGIS FeatureServer at the county level. Each county receives a composite risk score plus individual hazard risk breakdowns for all 18 hazard types. We preserve the NRI's own risk rating categories rather than creating our own scoring system.

We do not merge the three sources into a combined risk score, they measure different things and cover different time periods. Hazard profiles show all three datasets side by side so users can assess historical exposure from multiple angles.

Data Currency

FEMA disaster declaration data on PlainHazard covers 1973 to the present (the earliest year with complete digitized OpenFEMA records; the declaration program itself dates to 1953). The OpenFEMA API is updated as new disaster declarations are issued; our database reflects the most recent download. NOAA storm event data covers 2015 through 2025, with records released by NCEI on a rolling basis as state offices submit finalized reports.

PlainHazard currently uses FEMA's 2023 National Risk Index release; newer FEMA releases are adopted only after they have been validated and loaded into our database. We periodically refresh all three datasets as new records become available, and each page identifies the relevant source window.

Users should note that recent events may take weeks or months to appear in federal databases due to normal reporting and verification timelines at both the state and federal level.

Editorial Independence

Content on PlainHazard is compiled by our editorial team. Raw data from FEMA, NOAA, and the FEMA National Risk Index is transformed into readable profiles by our data-publishing pipeline. The PlainHazard editorial team is responsible for editorial standards, methodology, and corrections; source figures and PlainHazard-derived comparisons are labeled separately.

We do not accept payment, sponsorship, or promoted placement from government agencies, environmental organizations, or any covered entity. Our only revenue source is contextual display advertising served by Google AdSense, advertisers do not influence which entities we cover or how we present data, and they do not receive preferential placement.

Limitations and Disclaimers

This site is for informational purposes only. Users should understand the following limitations:

• Historical data, not forecasts: PlainHazard presents what has happened, not what will happen. Past disaster frequency does not predict future risk with certainty. Climate patterns, development, and mitigation efforts all affect future hazard exposure.
• Reporting gaps: NOAA storm event data depends on local reporting. Some events, especially in rural or sparsely populated areas, may be underreported. FEMA declarations require a presidential declaration threshold, so many significant local disasters do not appear in the FEMA dataset.
• Damage estimates are approximate: Property and crop damage figures from NOAA are estimates provided at the time of reporting and may not reflect final assessed losses. Figures are in nominal dollars and are not adjusted for inflation.
• Not for emergency decisions: Do not rely solely on this data for personal safety decisions, evacuation planning, or insurance underwriting. Always follow official guidance from local emergency management agencies, the National Weather Service, and FEMA.
• Not affiliated with government: PlainHazard is not affiliated with FEMA, NOAA, the National Weather Service, or any U.S. government agency. Official data should always be verified at the source.

Contact

For questions, data corrections, or feedback about PlainHazard, please reach out to us at hello@plainhazard.com. We welcome reports of data discrepancies or suggestions for additional hazard data we should include.

If you notice missing disaster records for your county or discrepancies between our data and official FEMA or NOAA records, please include the county name and specific event details so we can investigate and correct the data promptly.