How to check a home's flood risk
Updated 2026-07-11
To check a home's flood risk, look up its flood zone in FEMA's National Flood Hazard Layer, then weigh its elevation, distance to water, and history of past flooding. RiskMap does this for you: enter any U.S. address and it reads FEMA and related public-agency data into a clear flood risk read in seconds — no account required.
What flood risk actually measures
Flood risk is the chance that water reaches a specific location and how deep it could get. It is shaped by where a property sits relative to rivers, coasts, and low ground; how much rain or storm surge an area gets; how the surrounding land drains; and what has flooded before. A home just outside a mapped high-risk zone can still flood — flood maps describe likelihood, not a guarantee.
The public data behind it
Most flood risk information comes from free U.S. public sources:
- FEMA Flood Map Service Center — official flood zone maps (the National Flood Hazard Layer) for a specific address (msc.fema.gov).
- FEMA National Risk Index — county- and tract-level ratings for flooding and other hazards (hazards.fema.gov/nri).
- USGS — streamflow and water data that show how nearby waterways behave.
- NOAA / National Weather Service — rainfall, storm surge, and flood-warning information.
What a flood zone tells you — and what it doesn't
A FEMA flood zone tells you the mapped likelihood of flooding and whether lenders will require flood insurance. It does not capture every source of flooding — heavy-rain "pluvial" flooding, aging drainage, and recent development can all raise real-world risk beyond what a map shows. Treat the flood zone as a strong starting point, then add elevation and local history for a fuller picture.
How RiskMap surfaces flood risk
RiskMap reads FEMA flood data and related public-agency hazard data for a location and presents it as part of a clear, deterministic risk read — shown alongside wildfire, crime, environmental, and live-condition factors so you see flood risk in context, not in isolation. The score is benchmarked against national and state averages, and every data source is named in the app.
What to do next
- Look up the address in the FEMA Flood Map Service Center for its official zone.
- Check elevation and the property's history of flooding or claims.
- Ask about flood insurance — standard homeowners policies usually exclude flood.
- Open RiskMap to see flood risk alongside the location's other hazards at a glance.
Related: What is a wildfire risk score? · Home insurance risk factors
Check any U.S. address. RiskMap scores flood risk from public-agency data — free on iPhone and iPad.
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