Data sources and methodology

Last updated 6 Nov 2026

Source

OpenFEMA Dataset: Disaster Declarations Summaries – v2, published by the Federal Emergency Management Agency through OpenFEMA. FEMA updates it about every 20 minutes. The data is US government work in the public domain.

Current snapshot

How the data is processed

1. Once a day the full FEMA file is downloaded in a single request.
2. Each row is checked: required fields present, a known declaration type (DR, EM or FM), a known state or territory code, dates that parse, and 2- and 3-digit FIPS codes.
3. FEMA publishes one row per designated area. Rows are grouped into one declaration by FEMA's declaration ID (for example DR-4834-NC). If rows of the same declaration disagree on its title, type or dates, the update stops and the previous day's data stays online.
4. If the new file has more than 1% fewer rows than the last good one, the update also stops.
5. Pages are rebuilt from the checked data. Nothing is edited by hand.

What the numbers mean

• Counts are counts of FEMA declarations, not of events. One storm can lead to several declarations in several states.
• These figures count FEMA declarations and designated areas. They do not measure damage, cost, deaths or how severe an event was.
• A county is counted once per declaration that names it. Declarations covering a whole state are counted for the state, not for each county.
• Programme flags (Individual Assistance, Public Assistance, Hazard Mitigation) can differ between areas of the same declaration. A declaration is shown as having a programme if it was declared for at least one area; each area's own programmes are listed on the declaration page.
• Individual Assistance combines FEMA's two fields for it (ihProgramDeclared and iaProgramDeclared), as FEMA's own guidance recommends.
• Titles are converted from FEMA's capital letters to normal case. Area names are shown exactly as FEMA writes them.

Maps and charts

• County maps are drawn from US Census Bureau cartographic boundary files (1:10,000,000 scale, via the us-atlas package). Shades use the same five ranges on every state page (1–10, 11–20, 21–30, 31–40, 41 or more declarations) so states can be compared.
• Areas FEMA names that are not current counties, such as tribal lands or renamed areas, cannot be drawn and are listed in each state's table instead.
• Charts count declarations by the calendar year FEMA declared them. The current year is shown lighter because it is incomplete.
• Every chart has a table of the same numbers, and every map has a table of every area.

Known limits

• County-level areas are only recorded from 1964 onward, and FEMA notes that its older fire management records are partial.
• FEMA describes the data as raw entries from its emergency management system, with a small rate of human error. DisasterTrack does not correct FEMA's records.
• Declarations for Tribal Nations appear within the state where they are located.
• DisasterTrack does not show damage, costs, deaths or the severity of events.
• ZIP-code search is not offered because FEMA designates counties, not ZIP codes, and a ZIP code can cross county lines.
• Pages for individual declarations currently cover 2020 onward. Older declarations link to FEMA's own pages.

Freshness

Every data page shows when the data was last retrieved. If that is more than 48 hours ago, the page shows a notice that FEMA may have newer records.

Citation and attribution

Source: Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries – v2. Retrieved 5 Nov 2026, 18:35 UTC. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

FEMA's citation requirements: OpenFEMA terms and conditions.

Corrections

If something on this site does not match FEMA's record, please tell us. Errors in FEMA's own data should be reported to FEMA.