Wyoming inland flooding risk
Natrona County has the highest inland flooding risk in Wyoming, scoring 74.7 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index. Recorded inland flooding events across Wyoming have decreased 39% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Natrona County | 74.7 | Relatively Moderate | 6 |
| 2 | Sheridan County | 74.4 | Relatively Moderate | 3 |
| 3 | Laramie County | 67 | Relatively Low | 39 |
| 4 | Fremont County | 66.5 | Relatively Low | 34 |
| 5 | Park County | 60.8 | Relatively Low | 11 |
| 6 | Big Horn County | 52.4 | Relatively Low | 7 |
| 7 | Sweetwater County | 52.4 | Relatively Low | 5 |
| 8 | Carbon County | 50.3 | Relatively Low | 3 |
| 9 | Washakie County | 48.6 | Relatively Low | 8 |
| 10 | Albany County | 44.1 | Relatively Low | 16 |
| 11 | Converse County | 40.4 | Relatively Low | 2 |
| 12 | Campbell County | 40.2 | Relatively Low | 2 |
| 13 | Hot Springs County | 39.4 | Relatively Low | 1 |
| 14 | Johnson County | 36.9 | Relatively Low | 8 |
| 15 | Lincoln County | 35.5 | Relatively Low | 9 |
| 16 | Teton County | 34.7 | Very Low | 2 |
| 17 | Uinta County | 34.1 | Very Low | 0 |
| 18 | Platte County | 33.2 | Very Low | 18 |
| 19 | Goshen County | 31 | Very Low | 19 |
| 20 | Sublette County | 21.4 | Very Low | 5 |
| 21 | Crook County | 20.1 | Very Low | 8 |
| 22 | Weston County | 8.2 | Very Low | 5 |
| 23 | Niobrara County | 6.9 | Very Low | 1 |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Inland Flooding risk nationally:
Other hazard risks in Wyoming:
Frequently asked questions
What is the highest inland flooding risk county in Wyoming?
Natrona County, WY has the highest inland flooding risk in Wyoming, with a FEMA National Risk Index score of 74.7 out of 100 (rated "Relatively Moderate").
What causes inland flooding risk in Wyoming?
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.