Based on NOAA Storm Events Database records from 1996 to 2025, these are the Idaho counties with the most recorded flood events. Bannock County tops the list with 62 events. The data includes river floods, flash floods, coastal flooding, and hurricane-related flooding.
| Rank | County | Total Events | River Floods | Flash Floods |
|---|---|---|---|---|
| 1 | Bannock County | 62 | 22 | 40 |
| 2 | Kootenai County | 36 | 31 | 5 |
| 3 | Latah County | 32 | 24 | 8 |
| 4 | Power County | 32 | 4 | 28 |
| 5 | Blaine County | 29 | 15 | 14 |
| 6 | Nez Perce County | 28 | 14 | 14 |
| 7 | Shoshone County | 27 | 24 | 3 |
| 8 | Boise County | 26 | 6 | 20 |
| 9 | Cassia County | 25 | 3 | 22 |
| 10 | Owyhee County | 24 | 6 | 18 |
| 11 | Ada County | 23 | 13 | 10 |
| 12 | Bonner County | 23 | 22 | 1 |
| 13 | Lemhi County | 23 | 7 | 16 |
| 14 | Bonneville County | 20 | 14 | 6 |
| 15 | Benewah County | 19 | 18 | 1 |
| 16 | Madison County | 19 | 13 | 6 |
| 17 | Custer County | 18 | 8 | 10 |
| 18 | Elmore County | 18 | 5 | 13 |
| 19 | Oneida County | 18 | 4 | 14 |
| 20 | Idaho County | 17 | 5 | 12 |
| 21 | Boundary County | 16 | 13 | 3 |
| 22 | Fremont County | 16 | 9 | 7 |
| 23 | Bingham County | 15 | 10 | 5 |
| 24 | Washington County | 14 | 10 | 4 |
| 25 | Butte County | 11 | 8 | 3 |
| 26 | Caribou County | 11 | 8 | 3 |
| 27 | Jefferson County | 11 | 10 | 1 |
| 28 | Valley County | 10 | 4 | 6 |
| 29 | Twin Falls County | 10 | 2 | 8 |
| 30 | Bear Lake County | 9 | 8 | 1 |
| 31 | Canyon County | 9 | 7 | 2 |
| 32 | Clark County | 9 | 7 | 2 |
| 33 | Franklin County | 7 | 3 | 4 |
| 34 | Teton County | 7 | 4 | 3 |
| 35 | Clearwater County | 6 | 5 | 1 |
| 36 | Adams County | 5 | 3 | 2 |
| 37 | Gem County | 5 | 5 | 0 |
| 38 | Minidoka County | 5 | 5 | 0 |
| 39 | Camas County | 4 | 0 | 4 |
| 40 | Gooding County | 4 | 4 | 0 |
| 41 | Jerome County | 4 | 4 | 0 |
| 42 | Lincoln County | 4 | 4 | 0 |
| 43 | Payette County | 4 | 3 | 1 |
| 44 | Lewis County | 4 | 4 | 0 |
Source: NOAA Storm Events Database (1996–2025).
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