Property risk snapshot
Enter a US address to see three things: the FEMA flood zone at that point, FEMA's National Risk Index ratings for its census tract, and the days with NOAA hail and wind reports nearby. Each is a public data set, and each rates or maps a different thing, so read them side by side rather than as one score.
Public data, not a flood determination or an insurance assessment.
What each data set is
The flood zone comes from FEMA's National Flood Hazard Layer (NFHL), the database of current effective flood hazard data built from FEMA's effective flood maps and Letters of Map Change.
FEMA says NFHL digital data covers over 90% of the US population, and new data is added continuously.1
The National Risk Index is a FEMA data set that gives each US county and census tract a baseline measure of natural hazard risk relative to the rest. Its risk value multiplies expected annual loss by a community risk factor set by social vulnerability and community resilience.
The index covers 18 natural hazards. The tool shows the composite rating and 10 of the 18.2
The hail and wind lines count days with reports in the Storm Prediction Center's storm reports, which SPC plots from NWS Local Storm Reports by day, from 1200 UTC to 1159 UTC the next day.3
How to read the results
- Zones starting with A or V are Special Flood Hazard Areas, the land a 1-percent-annual-chance flood would cover. There, NFIP floodplain management rules must be enforced and the mandatory purchase of flood insurance applies.4,5
- Shaded Zone X (or Zone B) is moderate flood hazard, between the 1-percent and 0.2-percent-annual-chance floods. Unshaded Zone X (or Zone C) is minimal flood hazard.4
- National Risk Index ratings run Very Low, Relatively Low, Relatively Moderate, Relatively High and Very High. FEMA sorts all census tracts into these five groups by k-means clustering, so each rating compares a tract with every other US census tract.2
- Some ratings mark missing data. Not Applicable means no historical record and a hazard that is not geographically possible there, such as coastal flooding inland. Insufficient Data means a factor needed for the calculation is missing. No Rating means expected annual loss is zero.2
- The NWS defines a severe thunderstorm as one producing hail at least 1 inch in diameter, wind gusts of 58 mph or greater, or a tornado.6
Limits
FEMA says there is still a risk of flooding in low and moderate risk areas: from 2014 to 2024, nearly one-third of NFIP flood claims came from outside high-risk flood areas.7
The National Risk Index rates the census tract, not the building. Tracts are county subdivisions of about 4,000 people, and FEMA says a hazard can still occur and cause adverse impacts in an area with a low rating.2
The index does not explicitly account for forecasts, real-time hazard data or business disruption, and counts levees, dams and other flood control structures only where its source data include them.2
SPC's storm report list is preliminary and likely does not contain all severe weather reports for an event. The NCEI Storm Events Database holds the official, final data.6
To use NFHL data for official purposes, FEMA says the user is responsible for making sure base map data meet FEMA's accuracy standards and that locations are interpreted properly.1
Questions
- How do I find the flood zone for an address?
- FEMA's NFHL Viewer and its Flood Map Service Center both have an address search that shows the current effective flood hazard data, and both can produce a FIRMette, a smaller printable version of the Flood Insurance Rate Map.1
- Does Zone X mean a building won't flood?
- No. FEMA says nearly one-third of NFIP claims from 2014 to 2024 came from outside high-risk flood areas.7
- What does Relatively Moderate mean in the National Risk Index?
- It is the middle of five ratings, from Very Low to Very High, comparing the tract with every other US census tract.2
- Why does a place known for a hazard have a low National Risk Index rating?
- The people or property there may be less vulnerable to the hazard, or the community more resilient when it hits. Lower social vulnerability or higher community resilience can make the rating low even when expected annual loss is high.
Cloudbreak
Cloudbreak's proprietary predictive storm engine, built with AI and backed by meteorologists, tracks every storm against every building, before it hits and after it passes.
Sources
The address goes to Cloudbreak's app, which finds its map point with Geocodio, a geocoding service. The app keeps the matched address and point for 30 days, filed under a one-way hash of what was typed, so a repeat lookup skips the geocode. Only the map point goes to FEMA, and this site keeps FEMA's answers for a week by the point rounded to about 35 feet. The address is never sent to analytics.
- 1. FEMA: Flood Data Viewers and Geospatial Data
- 2. FEMA: National Risk Index Dataset (Dec. 2025 v1.20): Frequently Asked Questions
- 3. NOAA Storm Prediction Center: Storm Prediction Center Severe Weather Summaries
- 4. FEMA: Flood Zones
- 5. FEMA: Special Flood Hazard Area (SFHA)
- 6. NOAA Storm Prediction Center: SPC Frequently Asked Questions
- 7. FEMA National Flood Insurance Program: What Is My Flood Risk