Updated May 2026
Flood Risk in Iowa
Iowa carries a relatively low statewide average risk score of 12, with 100% of its 100 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 342 total claims.
Grade Distribution Across Iowa
The grade mix is dominated by A — 99% 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 Iowa Compares Nationally
The U.S. county-level average composite score is 12. Iowa sits at 12, which is right around the national average. 826 federal flood-related disaster declarations across 100 counties is one of the highest counts in the dataset — about 8.3 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.
How Iowa's Risk Is Calculated
Every county in Iowa 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 100 Counties in Iowa
Sorted by flood risk score, highest to lowest.
| # | County | Grade | Score | Claims | Payouts | Disasters |
|---|---|---|---|---|---|---|
| 1 | Scott | B | 22 | 44 | $1,232,770 | 12 |
| 2 | Clinton | A | 18 | 6 | $29,442 | 13 |
| 3 | Clayton | A | 16 | 3 | $5,003 | 15 |
| 4 | Allamakee | A | 15 | 0 | $0 | 13 |
| 5 | Johnson | A | 15 | 3 | $43,339 | 13 |
| 6 | Des Moines | A | 14 | 25 | $264,785 | 14 |
| 7 | Buchanan | A | 14 | 6 | $19,100 | 12 |
| 8 | Butler | A | 14 | 9 | $440,429 | 12 |
| 9 | Louisa | A | 14 | 1 | $0 | 12 |
| 10 | Pottawattamie | A | 14 | 20 | $460,412 | 8 |
| 11 | Linn | A | 14 | 29 | $139,211 | 12 |
| 12 | Dubuque | A | 13 | 3 | $6,082 | 11 |
| 13 | Lee | A | 13 | 2 | $48,169 | 10 |
| 14 | Fayette | A | 13 | 3 | $79,560 | 11 |
| 15 | Franklin | A | 13 | 0 | $0 | 11 |
| 16 | Iowa | A | 13 | 1 | $9,223 | 10 |
| 17 | Marshall | A | 13 | 0 | $0 | 10 |
| 18 | Tama | A | 13 | 2 | $21,671 | 11 |
| 19 | Wapello | A | 13 | 1 | $6,314 | 10 |
| 20 | Winneshiek | A | 13 | 4 | $47,495 | 10 |
| 21 | Fremont | A | 13 | 12 | $350,066 | 10 |
| 22 | Harrison | A | 13 | 4 | $130,309 | 10 |
| 23 | Muscatine | A | 13 | 7 | $82,905 | 11 |
| 24 | Marion | A | 13 | 0 | $0 | 10 |
| 25 | Black Hawk | A | 13 | 30 | $643,387 | 10 |
| 26 | Jackson | A | 12 | 2 | $2,402 | 9 |
| 27 | Audubon | A | 12 | 0 | $0 | 8 |
| 28 | Buena Vista | A | 12 | 0 | $0 | 8 |
| 29 | Carroll | A | 12 | 0 | $0 | 8 |
| 30 | Cass | A | 12 | 0 | $0 | 8 |
| 31 | Clay | A | 12 | 12 | $977,351 | 8 |
| 32 | Crawford | A | 12 | 0 | $0 | 9 |
| 33 | Dickinson | A | 12 | 4 | $137,353 | 8 |
| 34 | Emmet | A | 12 | 0 | $0 | 9 |
| 35 | Floyd | A | 12 | 5 | $26,123 | 9 |
| 36 | Greene | A | 12 | 0 | $0 | 8 |
| 37 | Hamilton | A | 12 | 0 | $0 | 8 |
| 38 | Howard | A | 12 | 3 | $16,698 | 9 |
| 39 | Jones | A | 12 | 1 | $1,430 | 9 |
| 40 | Keokuk | A | 12 | 0 | $0 | 9 |
| 41 | Kossuth | A | 12 | 0 | $0 | 8 |
| 42 | Madison | A | 12 | 0 | $0 | 9 |
| 43 | Mahaska | A | 12 | 0 | $0 | 8 |
| 44 | Monroe | A | 12 | 0 | $0 | 8 |
| 45 | Palo Alto | A | 12 | 0 | $0 | 8 |
| 46 | Polk | A | 12 | 37 | $1,944,812 | 9 |
| 47 | Ringgold | A | 12 | 0 | $0 | 9 |
| 48 | Webster | A | 12 | 0 | $0 | 8 |
| 49 | Wright | A | 12 | 1 | $2,369 | 9 |
| 50 | Mills | A | 12 | 6 | $442,689 | 8 |
| 51 | Monona | A | 12 | 0 | $0 | 8 |
| 52 | Woodbury | A | 12 | 8 | $140,869 | 8 |
| 53 | Cedar | A | 12 | 0 | $0 | 8 |
| 54 | Benton | A | 12 | 4 | $95,216 | 9 |
| 55 | Delaware | A | 12 | 3 | $91,442 | 9 |
| 56 | Sac and Fox Tribe of the Mississippi in Iowa | A | 11 | 0 | $0 | 7 |
| 57 | Adams | A | 11 | 0 | $0 | 6 |
| 58 | Appanoose | A | 11 | 0 | $0 | 6 |
| 59 | Boone | A | 11 | 0 | $0 | 6 |
| 60 | Cherokee | A | 11 | 4 | $129,324 | 7 |
| 61 | Dallas | A | 11 | 1 | $2,933 | 7 |
| 62 | Davis | A | 11 | 0 | $0 | 7 |
| 63 | Decatur | A | 11 | 0 | $0 | 7 |
| 64 | Hancock | A | 11 | 0 | $0 | 6 |
| 65 | Hardin | A | 11 | 1 | $0 | 7 |
| 66 | Henry | A | 11 | 0 | $0 | 7 |
| 67 | Humboldt | A | 11 | 0 | $0 | 7 |
| 68 | Ida | A | 11 | 0 | $0 | 7 |
| 69 | Jasper | A | 11 | 5 | $432,680 | 7 |
| 70 | Lucas | A | 11 | 0 | $0 | 7 |
| 71 | Lyon | A | 11 | 5 | $69,239 | 7 |
| 72 | Mitchell | A | 11 | 1 | $3,510 | 7 |
| 73 | Montgomery | A | 11 | 1 | $5,524 | 7 |
| 74 | Osceola | A | 11 | 0 | $0 | 7 |
| 75 | Page | A | 11 | 0 | $0 | 7 |
| 76 | Plymouth | A | 11 | 0 | $0 | 7 |
| 77 | Pocahontas | A | 11 | 0 | $0 | 7 |
| 78 | Sac | A | 11 | 0 | $0 | 6 |
| 79 | Sioux | A | 11 | 5 | $429,057 | 6 |
| 80 | Union | A | 11 | 0 | $0 | 7 |
| 81 | Wayne | A | 11 | 0 | $0 | 6 |
| 82 | Winnebago | A | 11 | 0 | $0 | 6 |
| 83 | Worth | A | 11 | 0 | $0 | 6 |
| 84 | Shelby | A | 11 | 0 | $0 | 7 |
| 85 | Jefferson | A | 11 | 0 | $0 | 7 |
| 86 | Van Buren | A | 11 | 0 | $0 | 7 |
| 87 | Warren | A | 11 | 0 | $0 | 7 |
| 88 | Cerro Gordo | A | 11 | 2 | $8,625 | 7 |
| 89 | Clarke | A | 11 | 0 | $0 | 7 |
| 90 | Story | A | 11 | 0 | $0 | 7 |
| 91 | Adair | A | 10 | 0 | $0 | 5 |
| 92 | Calhoun | A | 10 | 0 | $0 | 5 |
| 93 | Guthrie | A | 10 | 0 | $0 | 5 |
| 94 | O'Brien | A | 10 | 0 | $0 | 5 |
| 95 | Grundy | A | 10 | 0 | $0 | 5 |
| 96 | Poweshiek | A | 10 | 0 | $0 | 5 |
| 97 | Washington | A | 10 | 0 | $0 | 5 |
| 98 | Chickasaw | A | 9 | 7 | $63,169 | 9 |
| 99 | Taylor | A | 9 | 0 | $0 | 3 |
| 100 | Bremer | A | 8 | 9 | $174,396 | 9 |
Frequently Asked Questions
What is the average flood risk score in Iowa?
Iowa's average composite flood risk score is 12 on a 0–100 scale, computed as the mean of all 100 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 Iowa have the highest flood risk?
The riskiest county in Iowa is Scott with a composite score of 22 (grade B). The next four — Clinton, Clayton, Allamakee, Johnson — round out the top-five most exposed places in the state.
How many NFIP flood-insurance claims has Iowa filed?
FEMA's National Flood Insurance Program shows 342 claims on file from Iowa, with combined payouts of $9,256,883 across the dataset. 44 of the state's 100 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 Iowa 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 Iowa: 100 counties, 342 NFIP claims, average composite score 12.
The this entity record above pulls directly from FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims. What follows is the per-entity context — how this entity sits in the broader U.S. flood risk, NFIP claims, and disaster declarations distribution and which underlying factors drive the headline numbers.
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.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for this entity’s peers within U.S. ZIPs, counties, and states. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.