Top counties by inland flooding risk
Inland flooding covers riverine and surface (pluvial) flooding — the most common and costly natural disaster type in the US. High scores appear across river floodplains in the Midwest, South, and Mid-Atlantic, where legacy development in flood-prone areas and aging stormwater infrastructure concentrate risk.
3,144 counties scored 26 rated Very High Showing top 50
| # | County | State | NRI score | Rating | NOAA events 2016–2026 |
|---|---|---|---|---|---|
| 1 | Los Angeles County | CA | 100 | Very High | 107 |
| 2 | Harris County | TX | 100 | Very High | 98 |
| 3 | Maricopa County | AZ | 99.9 | Very High | 505 |
| 4 | Riverside County | CA | 99.9 | Very High | 210 |
| 5 | Cook County | IL | 99.9 | Very High | 221 |
| 6 | Orange County | CA | 99.8 | Very High | 75 |
| 7 | San Bernardino County | CA | 99.8 | Very High | 448 |
| 8 | Santa Clara County | CA | 99.8 | Very High | 117 |
| 9 | Alameda County | CA | 99.7 | Very High | 144 |
| 10 | San Diego County | CA | 99.7 | Very High | 250 |
| 11 | Miami-Dade County | FL | 99.7 | Very High | 137 |
| 12 | Bexar County | TX | 99.7 | Very High | 181 |
| 13 | Clark County | NV | 99.6 | Very High | 140 |
| 14 | Philadelphia County | PA | 99.6 | Very High | 101 |
| 15 | Dallas County | TX | 99.6 | Very High | 132 |
| 16 | Pima County | AZ | 99.5 | Very High | 202 |
| 17 | Contra Costa County | CA | 99.5 | Very High | 49 |
| 18 | King County | WA | 99.5 | Very High | 1 |
| 19 | Broward County | FL | 99.4 | Very High | 87 |
| 20 | Wayne County | MI | 99.4 | Very High | 35 |
| 21 | Kings County | NY | 99.4 | Very High | 31 |
| 22 | Ventura County | CA | 99.3 | Very High | 46 |
| 23 | Honolulu County | HI | 99.3 | Very High | 68 |
| 24 | Queens County | NY | 99.3 | Very High | 67 |
| 25 | Sonoma County | CA | 99.2 | Relatively High | 238 |
| 26 | New York County | NY | 99.2 | Very High | 20 |
| 27 | Allegheny County | PA | 99.2 | Very High | 328 |
| 28 | Jefferson County | KY | 99.1 | Relatively High | 106 |
| 29 | St. Louis County | MO | 99.1 | Relatively High | 31 |
| 30 | Tarrant County | TX | 99.1 | Relatively High | 94 |
| 31 | Sacramento County | CA | 99 | Relatively High | 148 |
| 32 | Erie County | NY | 99 | Relatively High | 51 |
| 33 | Mecklenburg County | NC | 99 | Relatively High | 30 |
| 34 | Capitol Planning Region | CT | 99 | Relatively High | 0 |
| 35 | Palm Beach County | FL | 98.9 | Relatively High | 75 |
| 36 | Hawaii County | HI | 98.9 | Relatively High | 55 |
| 37 | Middlesex County | NJ | 98.9 | Relatively High | 92 |
| 38 | Bergen County | NJ | 98.8 | Relatively High | 162 |
| 39 | Essex County | NJ | 98.8 | Relatively High | 75 |
| 40 | Franklin County | OH | 98.8 | Relatively High | 82 |
| 41 | Fresno County | CA | 98.7 | Relatively High | 271 |
| 42 | Cuyahoga County | OH | 98.7 | Relatively High | 54 |
| 43 | Shelby County | TN | 98.7 | Relatively High | 79 |
| 44 | San Francisco County | CA | 98.6 | Relatively High | 78 |
| 45 | Santa Barbara County | CA | 98.6 | Relatively High | 47 |
| 46 | Hudson County | NJ | 98.6 | Relatively High | 66 |
| 47 | Kern County | CA | 98.5 | Relatively High | 319 |
| 48 | Middlesex County | MA | 98.5 | Relatively High | 129 |
| 49 | Bronx County | NY | 98.5 | Relatively High | 28 |
| 50 | San Mateo County | CA | 98.4 | Relatively High | 55 |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties — a score of 95 means this county's expected annual loss from inland flooding exceeds 95% of all other counties. See the methodology page for definitions. Download the full CSV for all 3,144 scored counties.
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