PlainHazard guide
How to Use Hazard Data for Preparedness
Know the hazards you're preparing for
- 835,622
- NOAA storm events tracked
- 54
- Distinct storm-hazard types
- Thunderstorm Wind
- Most common storm hazard
Most common storm hazards in the U.S.
NOAA-recorded event counts by hazard type, the events you're most likely to face
- Thunderstorm Wind
Thunderstorm Wind
234,600 events
- Hail
Hail
113,479 events
- Flash Flood 54,405
Flash Flood
54,405 events
- High Wind 50,942
High Wind
50,942 events
- Winter Weather 50,010
Winter Weather
50,010 events
- Drought 44,239
Drought
44,239 events
- Winter Storm 37,855
Winter Storm
37,855 events
- Flood 35,032
Flood
35,032 events
What this shows Knowing which hazards recur in your area is the first step in preparedness; look up your county's profile to see its specific risk mix before you build a plan.
Understanding your area's historical hazard exposure using FEMA and NOAA data, and how that context supports preparedness planning.
Key Takeaway
Historical disaster data doesn't tell you when the next event will occur, but it reliably tells you what types of hazards your area faces and how often federal resources have been mobilized. Knowing your local hazard profile lets you match your preparedness efforts to real geographic risks rather than generic checklists.
Important Safety Notice
This content is for informational purposes only. Always follow official guidance from local authorities and emergency services. In an active emergency, follow instructions from FEMA, NOAA, NWS, and local emergency management, not this site.
Step 1: Find Your County's Declaration History
Start with the county profiles section. Search for your county to see:
- Total FEMA declarations - How many times has federal disaster assistance been mobilized for your county since 1973?
- Declaration types - Are these major disaster declarations (broad recovery aid), emergency declarations (protective response), or fire assistance grants (wildfire-specific)?
- Storm event counts - How many NOAA-documented severe weather events has your county experienced?
- Fatalities and damage - What have past events cost in lives and property in your area?
Counties with many declarations share a common pattern: geographic exposure to a recurring hazard type. This is the most reliable signal for ongoing risk.
Step 2: Identify Your Primary Hazard Types
After reviewing your county's overall declaration history, look at the hazard types section to identify which specific NOAA event categories dominate your state and region. The 55+ event types in the NOAA database represent meaningfully different threats requiring different preparedness responses.
If tornadoes dominate your region
Focus on shelter-in-place planning. Identify your home's strongest interior room away from windows. Know how to receive tornado warnings, NOAA Weather Radio, Wireless Emergency Alerts, and local sirens. Have a plan for weather events at night when visibility and warning time are reduced.
If floods are your primary hazard
Know your evacuation routes. Understand that standard homeowner's insurance does not cover flooding, the National Flood Insurance Program (NFIP) provides separate flood coverage. Never drive through flooded roadways; "Turn Around, Don't Drown" applies even to shallow water that can conceal dangerous currents.
If hurricanes are a regional threat
Develop both shelter-in-place and evacuation plans. Know your local evacuation zones and routes. Pre-season preparation, window protection, emergency supplies, fuel, matters because storms can make landfall with short notice timelines for preparation. Know the difference between a Watch (conditions possible in 48 hours) and a Warning (conditions expected in 36 hours).
If wildfires affect your region
Learn your community's evacuation routes and sign up for local emergency alerts. Create defensible space around structures in the wildland-urban interface. Have a go-bag ready with medications, documents, and essential supplies, wildfire evacuations can occur with less than an hour's notice.
Step 3: Understand Frequency Patterns
PlainHazard's state profiles show declaration counts by year, revealing frequency patterns. A state or county with disaster declarations in many of the last 10 years faces persistent exposure, annual or near-annual preparedness review is warranted. A state with occasional declarations still benefits from preparedness planning, but the urgency of regular review differs.
Frequency data is also useful for understanding seasonal risk windows. Hurricane season runs June through November, with peak activity in August-October. Tornado frequency peaks in spring across Tornado Alley and in spring and fall across Dixie Alley. Wildfire risk peaks in summer and fall in Western states during hot, dry conditions. Knowing your primary hazard's seasonal pattern helps focus preparedness actions at the right time of year.
What Historical Data Cannot Tell You
Federal hazard data is a powerful tool for understanding geographic exposure, but it has clear limitations for individual preparedness decisions:
- It does not predict timing. Historical frequency does not tell you when the next event will occur. A county with 20 flood declarations since 1973 does not necessarily have a flood every year.
- It does not account for local vulnerability. Your specific location within a county matters enormously. A county flood declaration does not mean all parts of the county flooded equally. Proximity to rivers, elevation, and soil type all affect actual flood risk at a parcel level.
- It is a lagging indicator. FEMA declarations and NOAA records document past events. Ongoing changes in land use, population density, and climate patterns may alter future risk in ways historical data does not capture.
- It does not replace local knowledge. Long-term residents and local emergency management officials often have detailed knowledge of which specific areas flood, which roads are always closed first, and where community gathering points are during emergencies, knowledge that no federal dataset fully captures.
Official Preparedness Resources
Use PlainHazard data as context. For action planning, these federal and state resources provide authoritative guidance:
- FEMA Ready.gov: ready.gov - Emergency kits, family communication plans, and hazard-specific preparation guides.
- NOAA National Weather Service: weather.gov - Real-time watches, warnings, and advisories. Local office hazard climatologies.
- State emergency management agencies: Each state maintains a hazard mitigation plan and public preparedness resources. Find your state agency through FEMA's directory.
- Local emergency management: County and municipal offices have the most specific local guidance, including evacuation zone maps and shelter locations.
Data Sources
- FEMA OpenFEMA: Disaster Declarations Summaries v2 - federal disaster declarations since 1973, 56 states and territories, 2,729 counties.
- NOAA NCEI: Storm Events Database - 690,000+ storm events (2015-2025), 55+ hazard types.
Turn preparedness into action
835,622 tracked NOAA storm events confirm severe weather touches nearly every part of the country; find yours before you need to.
- Check your own state's dominant hazard mix and historical declaration count. Browse states
- Find your specific county's FEMA NRI risk score and per-hazard breakdown. Browse counties
- Thunderstorm Wind is the single most-tracked event type nationally, see how it compares where you live. Explore hazard types
This guide covers general preparedness principles; always follow official guidance from FEMA and local emergency management for your specific situation.
Frequently Asked Questions
How do I find historical disaster data for my county?
PlainHazard provides county-level FEMA declaration data for 2,729 US counties. Visit the Counties section and search for your county to see how many FEMA major disaster, emergency, and fire declarations have been issued for your area since 1973. County pages also show storm event counts from NOAA data. Historical frequency is one of the most reliable indicators of ongoing risk, areas with repeated declarations share common geographic and climatological exposure.
What does it mean if my county has many FEMA declarations?
A high number of FEMA declarations indicates that your county has experienced repeated events severe enough to overwhelm local and state resources and trigger federal aid. This is useful baseline context for preparedness planning. However, declarations also reflect administrative and political factors, not every high-risk county has frequent declarations, and some counties with many declarations are in regions where state governments have historically been proactive about requesting federal assistance. Use FEMA data alongside NOAA storm event counts for a more complete picture.
Can historical hazard data predict future risk?
Historical data is one of the most reliable indicators of ongoing geographic risk, but it is not a precise predictor of future events. Hazard exposure is driven by geography, climate patterns, and regional weather systems that change slowly, a county in a tornado-prone region will likely remain in a tornado-prone region. However, climate variability means that an area with a quiet decade of disaster history can still experience a catastrophic event. Use historical patterns to understand your general hazard exposure, not to conclude that your area is "safe" because of a quiet recent period.
What is the difference between hazard exposure and risk?
Hazard exposure refers to the physical threat, how often a location experiences floods, tornadoes, or hurricanes. Risk combines exposure with vulnerability: who is exposed, what structures exist, and what preparedness measures are in place. Two counties with identical NOAA storm event counts can have dramatically different outcomes depending on building quality, population density, early warning systems, and community preparedness resources. PlainHazard data helps you understand exposure. Organizations like FEMA, NOAA, and state emergency management agencies provide risk assessment tools that layer in vulnerability factors.
How do I use the PlainHazard hazard types data for preparedness?
The hazard types section shows which NOAA storm event categories occur most frequently in your state and region. Start by identifying the top 3-5 hazard types for your state. If your state shows high tornado activity, focus preparedness on shelter-in-place planning and NOAA weather radio alerts. If your state leads in flash flood events, focus on evacuation routes, flood insurance awareness, and avoiding flood-prone areas during storms. Matching your preparedness planning to your actual geographic hazard profile is more effective than generic emergency kits without threat context.
Where can I find official preparedness resources beyond this data?
FEMA's Ready.gov (ready.gov) is the primary federal preparedness resource, covering emergency kits, family plans, and hazard-specific guidance. The National Weather Service (weather.gov) provides real-time alerts and local hazard climatologies. Your state emergency management agency publishes state-specific preparedness guides and maintains hazard mitigation plans required by FEMA. Local emergency management offices often have the most specific local guidance. Always treat PlainHazard data as context for understanding your area's hazard history, official preparedness resources provide actionable guidance.