PlainHazard guide
Understanding FEMA Disaster Data
FEMA disaster data at a glance
- 1,017
- FEMA disaster declarations
- 767,231
- NOAA storm events
- 2,729
- U.S. counties covered
FEMA declarations by incident type
Which hazard categories drive the most federal disaster declarations
- Fire
Fire
588 declarations
- Severe Storm 150
Severe Storm
150 declarations
- Flood 83
Flood
83 declarations
- Hurricane 64
Hurricane
64 declarations
- Tropical Storm 35
Tropical Storm
35 declarations
- Winter Storm 30
Winter Storm
30 declarations
- Biological 14
Biological
14 declarations
- Severe Ice Storm 13
Severe Ice Storm
13 declarations
What this shows Severe storms and floods dominate FEMA's declaration record because they recur across many states and seasons; rarer hazards like earthquakes appear far less often.
A plain-language guide to what FEMA disaster declarations mean, how they differ from each other, and how NOAA storm records complement the picture.
Key Takeaway
FEMA disaster declarations represent the federal government's formal response to overwhelmed state resources, they are a lagging, policy-filtered view of disasters. NOAA storm records capture what actually happened on the ground, regardless of whether federal aid was requested. Together, both datasets give the most complete picture of US natural hazard history.
The Three Types of FEMA Declarations
FEMA's OpenFEMA dataset distinguishes three declaration types, each serving a different purpose and unlocking different categories of federal aid.
Major Disaster Declaration (DR)
The most comprehensive federal disaster response tool, authorized under the Stafford Act. Triggered by presidential approval of a governor's request after an event causes damage exceeding state and local capacity. Unlocks Individual Assistance (housing, medical, crisis counseling), Public Assistance (infrastructure repair), and Hazard Mitigation grants. Examples include Hurricane Katrina (2005), Superstorm Sandy (2012), and the 2011 Joplin tornado.
Emergency Declaration (EM)
A narrower authority used for events requiring immediate federal assistance to protect lives and property, or issued pre-emptively before a disaster strikes. Federal cost ceiling is approximately $5 million. Often issued before major hurricanes to pre-position resources. Less comprehensive than a major disaster declaration, it does not automatically unlock Individual Assistance programs for households.
Fire Management Assistance Grant (FM)
Specific to uncontrolled wildfires threatening communities. Can be declared within hours when a fire threatens to cause major damage. Covers only fire suppression costs, no individual or public assistance programs. Western states, particularly California, Oregon, and Washington, receive the most FMAGs annually given regional fire conditions. PlainHazard's hazard data tracks wildfire events from NOAA separately from FEMA fire declarations.
How a Disaster Gets Declared
The process from event to declaration follows a specific sequence. Understanding it helps explain why some devastating events don't result in FEMA declarations and why declaration counts reflect policy as much as disaster severity.
- Event occurs - A hurricane, flood, tornado, or other hazard causes damage.
- Local and state response - Local governments respond first, then request state emergency assistance.
- Preliminary damage assessment - FEMA and state officials jointly assess damage to determine whether federal thresholds are met.
- Governor's request - The governor formally requests a presidential disaster declaration.
- Presidential decision - The President approves or denies the request based on FEMA's recommendation. Approval rates have historically ranged from 60-75%.
Browse state-level disaster histories to see how many declarations each state has received and what types dominate.
What the NOAA Storm Events Database Captures
NOAA's Storm Events Database is distinct from FEMA data. It records weather events documented by National Weather Service meteorologists, regardless of whether federal aid was requested. This makes it a more complete picture of what actually occurred on the ground.
The database categorizes events into 55+ types covering thunderstorm winds, tornadoes, flash floods, coastal floods, hail, winter storms, blizzards, fog, drought, wildfires, dust storms, and tropical systems. Each record includes:
- Start and end date/time and location (state, county, coordinates)
- Direct and indirect fatalities and injuries
- Property damage and crop damage (in nominal dollars)
- Narrative description from the NWS office
PlainHazard's hazard type pages let you explore each NOAA event category across all states and counties.
Reading Damage Figures
NOAA damage estimates are reported in nominal dollars by NWS offices at the time of the event, they are not inflation-adjusted and may underestimate true economic losses. Large-scale events like major hurricanes have comprehensive damage estimates; smaller localized events may have rough approximations or be listed as zero if damage was not assessed.
FEMA's public dataset does not include detailed damage cost figures for individual declarations, it focuses on declaration type, affected areas, and program eligibility. Damage cost data from FEMA comes from separate program-level reports not included in PlainHazard's current dataset.
Cross-comparing FEMA, NOAA, and FEMA NRI
The three federal hazard datasets are complementary, not redundant. Researchers using PlainHazard often need to switch between them depending on the question being asked.
FEMA OpenFEMA, federal recognition of severity
OpenFEMA captures only events that crossed the federal-declaration threshold. Use it when the question is about federal aid, Public Assistance projects, or the political-administrative recognition of a disaster.
NOAA Storm Events Database, frequency and intensity
NOAA captures the broader severe-weather signal, including events that did not trigger a federal declaration. Use it when the question is about hazard frequency, climatological trends, or the population of localized events that never reached presidential attention.
FEMA NRI, modeled exposure and vulnerability
The National Risk Index is forward-looking. It combines historical hazard frequency with exposed-asset value, social vulnerability, and community resilience to model annualized loss for each county. Use it when the question is about future risk, insurance pricing, or pre-disaster planning.
Worked example: a Florida coastal county
A typical Florida coastal county might show this pattern across the three datasets:
| Dataset | Records | Loss / EAL | Question it answers |
|---|---|---|---|
| FEMA OpenFEMA | 12 declarations | $420M PA obligated | Federal recognition |
| NOAA Storm Events | 2,341 events | $890M nominal damage | Hazard frequency |
| FEMA NRI | 18 hazards modeled | $78M EAL/year | Forward exposure |
In this scenario, the county shows estimated $420M in federal Public Assistance obligated against $890M in nominal NOAA-reported damage and a modeled $78M EAL per year, the gap between $420M federal aid and $890M total damage represents uninsured and self-insured losses, while the EAL is what FEMA NRI expects in any given future year.
Worked example: declaration concentration
Across the FEMA dataset since 1973, fewer than 10% of US counties have received 15 or more disaster declarations, yet those counties account for 60% of national federal disaster spending. The other 90% of counties account for 40% - frequency and severity are concentrated, not evenly spread.
Note: Numbers above are illustrative ranges typical of a coastal Florida county for the worked-example pattern; PlainHazard's per-county pages show real values. Do not cite the table values for a specific county without checking that county's detail page directly.
Data Sources
- FEMA OpenFEMA: Disaster Declarations Summaries v2 - all federal disaster declarations since 1973.
- NOAA NCEI: Storm Events Database - severe weather event records maintained by the National Weather Service.
This content is for informational purposes only. Always follow official guidance from local authorities and emergency services.
Frequently Asked Questions
What is a FEMA major disaster declaration?
A major disaster declaration (DR) is issued by the President following a governor's request when a disaster overwhelms state and local resources. It unlocks the widest range of federal assistance programs, including Individual Assistance for households and Public Assistance for rebuilding infrastructure. Major disaster declarations are the most common type in the FEMA dataset, representing events like hurricanes, floods, tornadoes, and severe winter storms.
How does an emergency declaration differ from a major disaster declaration?
Emergency declarations (EM) are more limited in scope and can be issued in anticipation of an event or for smaller-scale situations. They primarily fund protective measures and emergency response costs rather than recovery. The federal cost ceiling for emergency declarations is typically $5 million, compared to major disaster declarations which can involve billions in aid. FEMA's dataset includes both types, and PlainHazard lets you filter by declaration type.
What is a Fire Management Assistance Grant (FMAG)?
Fire Management Assistance Grants (FM) help states, local, and tribal governments pay for suppressing uncontrolled fires that threaten communities. Unlike major disaster declarations, FMAGs are focused exclusively on wildfire firefighting costs and are declared much more frequently, often within hours of a fire threatening lives or property. Western states like California receive a disproportionate share of FMAGs given the regional fire environment.
What does NOAA track in the Storm Events Database?
NOAA's Storm Events Database, maintained by the National Centers for Environmental Information (NCEI), records severe weather events reported by the National Weather Service. It includes 55+ event types such as tornadoes, thunderstorm winds, flash floods, hail, winter storms, and tropical cyclones. Each record includes location, start/end times, fatalities, injuries, and property and crop damage estimates. PlainHazard covers 690,000+ events from 2015 through 2025.
Why do some disasters appear in NOAA data but not FEMA data?
NOAA records every qualifying severe weather event regardless of whether federal disaster aid was requested or granted. FEMA declarations require a governor's formal request and a presidential determination that state resources are overwhelmed. Many localized but destructive events, significant hail storms, flash floods affecting a single county, appear in NOAA data without triggering a FEMA declaration. Conversely, FEMA can declare disasters for non-weather events like droughts or chemical releases not in the NOAA storm events database.
Has the frequency of FEMA disaster declarations increased over time?
Yes, the number of annual FEMA major disaster declarations has grown substantially since 1973. In the 1960s, fewer than 20 declarations were issued per year nationally. By the 2010s and 2020s, that number routinely exceeds 50-70 per year. Researchers attribute this trend to a combination of factors: increased development in hazard-prone areas, better event detection and documentation, population growth in coastal and flood-prone zones, and changes in the political and administrative processes around disaster requests.
