Updated May 2026
Flood Risk in Delaware
Delaware carries a relatively low statewide average risk score of 12, with 100% of its 4 counties at A or B. 0 counties are in the F (extreme) tier, typically along major rivers or flood-prone basins. Statewide NFIP take-up is modest at 110 total claims.
Grade Distribution Across Delaware
The grade mix is dominated by A — 100% of counties — meaning the typical place in this state has very low historical flood loss. The handful of B/C/D/F counties below define where risk is concentrated.
How Delaware Compares Nationally
The U.S. county-level average composite score is 12. Delaware sits at 12, which is right around the national average. 26 federal flood-related disaster declarations across 4 counties is one of the highest counts in the dataset — about 6.5 per county. Most counties have lived through multiple federally declared floods.
For full national context — every state ranked by average score and total claims — see the all-states overview. The riskiest-counties ranking and highest-payouts ranking drill into where loss is concentrated. Real-time stream-gauge readings are at USGS Water Data.
Riskiest in Delaware
| County | Grade | Score |
|---|---|---|
| New Castle | A | 20 |
| Kent | A | 11 |
| Statewide | A | 8 |
| Sussex | A | 7 |
Safest in Delaware
| County | Grade | Score |
|---|---|---|
| Sussex | A | 7 |
| Statewide | A | 8 |
| Kent | A | 11 |
| New Castle | A | 20 |
How Delaware's Risk Is Calculated
Every county in Delaware is scored on the same four factors that drive every county nationwide: NFIP claims density (40%), federally declared flood-disaster frequency (25%), average claim severity (20%), and year-over-year trend (15%). Source data comes from the public FEMA flood-mapping program and OpenFEMA endpoints. Detailed weighting math, plus the data's known limitations (county-level granularity, NFIP-participation bias, historical bias), is on the methodology page.
All 4 Counties in Delaware
Sorted by flood risk score, highest to lowest.
| # | County | Grade | Score | Claims | Payouts | Disasters |
|---|---|---|---|---|---|---|
| 1 | New Castle | A | 20 | 39 | $617,579 | 9 |
| 2 | Kent | A | 11 | 7 | $67,281 | 8 |
| 3 | Statewide | A | 8 | 0 | $0 | 1 |
| 4 | Sussex | A | 7 | 64 | $748,940 | 8 |
Frequently Asked Questions
What is the average flood risk score in Delaware?
Delaware's average composite flood risk score is 12 on a 0–100 scale, computed as the mean of all 4 county scores. That is roughly equal to the U.S. county-level average of 12. Score components: 40% claims density, 25% disaster frequency, 20% claim severity, 15% trend.
Which counties in Delaware have the highest flood risk?
The riskiest county in Delaware is New Castle with a composite score of 20 (grade A). The next four — Kent, Statewide, Sussex — round out the top-five most exposed places in the state.
How many NFIP flood-insurance claims has Delaware filed?
FEMA's National Flood Insurance Program shows 110 claims on file from Delaware, with combined payouts of $1,433,800 across the dataset. 3 of the state's 4 counties have at least one NFIP claim recorded.
Are FEMA flood maps the same as your risk score?
No. The flood risk score on this page is a county-wide composite drawn from claims, disasters, severity, and trend. FEMA Flood Insurance Rate Maps (FIRMs, available at fema.gov/flood-maps) are parcel-level zone designations based on hydrologic modeling. The two answer different questions; serious decisions about insurance or building should use both, plus real-time hydrology from USGS Water Data.
When was the Delaware data last updated?
These figures were refreshed from the OpenFEMA API on 2026-05-16. FEMA itself publishes new NFIP claims on a quarterly cycle, so the data may lag actual events by up to three months.
Flood risk profile for Delaware: 4 counties, 110 NFIP claims, average composite score 12.
For this entity, the underlying data on this page comes from FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims. The breakdown above is the federal record; the paragraphs below add the per-entity context that makes the headline numbers usable for a real decision rather than just a data lookup.
The methodology behind every numeric value on this page is publicly documented on the FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. ZIPs, counties, and states with similar size, similar exposure, or similar geography — not the national-level summary alone.