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 | 56 | 51 | 5 |
| 3 | Latah County | 51 | 43 | 8 |
| 4 | Shoshone County | 39 | 36 | 3 |
| 5 | Benewah County | 38 | 37 | 1 |
| 6 | Power County | 32 | 4 | 28 |
| 7 | Blaine County | 29 | 15 | 14 |
| 8 | Bonner County | 28 | 27 | 1 |
| 9 | Nez Perce County | 28 | 14 | 14 |
| 10 | Owyhee County | 28 | 10 | 18 |
| 11 | Boise County | 27 | 7 | 20 |
| 12 | Lemhi County | 26 | 10 | 16 |
| 13 | Cassia County | 25 | 3 | 22 |
| 14 | Ada County | 24 | 14 | 10 |
| 15 | Idaho County | 23 | 11 | 12 |
| 16 | Boundary County | 21 | 18 | 3 |
| 17 | Fremont County | 21 | 14 | 7 |
| 18 | Washington County | 21 | 17 | 4 |
| 19 | Bonneville County | 20 | 14 | 6 |
| 20 | Elmore County | 20 | 7 | 13 |
| 21 | Madison County | 19 | 13 | 6 |
| 22 | Custer County | 18 | 8 | 10 |
| 23 | Oneida County | 18 | 4 | 14 |
| 24 | Bingham County | 15 | 10 | 5 |
| 25 | Valley County | 14 | 8 | 6 |
| 26 | Clearwater County | 13 | 12 | 1 |
| 27 | Canyon County | 12 | 10 | 2 |
| 28 | Gem County | 12 | 12 | 0 |
| 29 | Butte County | 11 | 8 | 3 |
| 30 | Caribou County | 11 | 8 | 3 |
| 31 | Jefferson County | 11 | 10 | 1 |
| 32 | Twin Falls County | 11 | 3 | 8 |
| 33 | Adams County | 9 | 7 | 2 |
| 34 | Bear Lake County | 9 | 8 | 1 |
| 35 | Clark County | 9 | 7 | 2 |
| 36 | Franklin County | 7 | 3 | 4 |
| 37 | Payette County | 7 | 6 | 1 |
| 38 | Teton County | 7 | 4 | 3 |
| 39 | Camas County | 5 | 1 | 4 |
| 40 | Gooding County | 5 | 5 | 0 |
| 41 | Jerome County | 5 | 5 | 0 |
| 42 | Minidoka County | 5 | 5 | 0 |
| 43 | Lincoln County | 4 | 4 | 0 |
| 44 | Lewis County | 4 | 4 | 0 |
Source: NOAA Storm Events Database (1996–2025).
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