Boise County, Idaho: hazard risk
FEMA rates Boise County's overall risk Relatively Low (score 48.9 of 100, higher than 48% of rated U.S. counties); 1 of its 15 hazards are rated Relatively High or Very High, led by avalanche. Its storm record holds 254 events since 1950.
FEMA's rating for each hazard
These are FEMA's county-wide model ratings and this county's storm record. They are not an assessment of any property, address or building, and not insurance advice: a property's risk depends on its own elevation, construction and location.
FEMA gives each hazard its own rating, and a rating does not follow the score from one hazard to the next: a hazard with a higher score can carry a lower rating than another. The table sorts by FEMA's rating, then by score (0 to 100, the county against every other county for that hazard).
| Hazard | Risk rating | Score | Expected annual loss |
|---|---|---|---|
| Avalanche | Relatively High | 87.6 | $1.4M |
| Landslide | Relatively Moderate | 97.3 | $356K |
| Wildfire | Relatively Moderate | 97.2 | $8.2M |
| Winter Weather | Relatively Low | 51.9 | $70K |
| Riverine Flooding | Relatively Low | 42.9 | $5.5M |
| Strong Wind | Relatively Low | 23.6 | $225K |
| Earthquake | Very Low | 40.0 | $158K |
| Volcanic Activity | Very Low | 31.9 | $3 |
| Heat Wave | Very Low | 14.9 | $36K |
| Ice Storm | Very Low | 13.2 | $8K |
| Drought | Very Low | 12.4 | $1 |
| Lightning | Very Low | 9.3 | $32K |
| Cold Wave | Very Low | 4.6 | $13K |
| Hail | Very Low | 4.5 | $11K |
| Tornado | Very Low | 4.0 | $13K |
Source: FEMA National Risk Index, December 2025 release. A model of future loss, not a count of past events. FEMA's National Risk Index map.
What the record holds
| Hazard | Records | Deaths | Damage | Rank in state | Rank in U.S. |
|---|---|---|---|---|---|
| Winter storms | 141 | 0 | – | 33rd of 44 | 1965th of 3,077 |
| Floods | 27 | 0 | $10M | 17th of 44 | 2603rd of 3,080 |
| Severe thunderstorm wind | 27 | 1 | $103K | 35th of 44 | 2828th of 3,080 |
| Hail | 21 | 0 | – | 26th of 44 | 2827th of 3,080 |
| Heavy rain | 19 | 0 | – | 6th of 44 | 1305th of 3,080 |
| High wind and dust storms | 12 | 0 | $13K | 40th of 44 | 2613th of 3,080 |
| Landslides and avalanches | 6 | 2 | – | 20th of 44 | 208th of 2,278 |
| Wildfires | 1 | 0 | – | 38th of 44 | 1230th of 2,972 |
Source: NOAA NCEI Storm Events Database, 1950 to 2026-06-30; damage in 2025 dollars. Search the record at NCEI.
The full Boise County record: every hazard by year and month, the deadliest events and FEMA's declarations.