Volcanic Activity Risk in Idaho
All Idaho counties ranked by FEMA National Risk Index volcanic activity score
Volcanic Activity risk — eruptions producing ashfall, lava, and pyroclastic hazards — is rated for 34 of 44 Idaho counties in FEMA's National Risk Index. Ada County carries the state's highest volcanic activity score at 74.3, with $235 in expected annual volcanic activity losses.
No Idaho county reaches the High band for volcanic activity, and expected annual losses from volcanic activity total roughly $1K statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Volcanic Activity
| # | County | Volcanic Activity Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | Ada County | Very Low | 0.00 / yr | $235 | |
| 2 | Bonneville County | Very Low | 0.00 / yr | $163 | |
| 3 | Canyon County | Very Low | 0.00 / yr | $110 | |
| 4 | Bannock County | Very Low | 0.00 / yr | $99 | |
| 5 | Bingham County | Very Low | 0.00 / yr | $78 | |
| 6 | Power County | Very Low | 0.00 / yr | $73 | |
| 7 | Madison County | Very Low | 0.00 / yr | $63 | |
| 8 | Jefferson County | Very Low | 0.00 / yr | $37 | |
| 9 | Butte County | Very Low | 0.00 / yr | $21 | |
| 10 | Blaine County | Very Low | 0.00 / yr | $24 | |
| 11 | Lincoln County | Very Low | 0.00 / yr | $19 | |
| 12 | Twin Falls County | Very Low | 0.00 / yr | $22 | |
| 13 | Minidoka County | Very Low | 0.00 / yr | $20 | |
| 14 | Fremont County | Very Low | 0.00 / yr | $16 | |
| 15 | Teton County | Very Low | 0.00 / yr | $13 | |
| 16 | Cassia County | Very Low | 0.00 / yr | $12 | |
| 17 | Payette County | Very Low | 0.00 / yr | $12 | |
| 18 | Jerome County | Very Low | 0.00 / yr | $7 | |
| 19 | Gem County | Very Low | 0.00 / yr | $9 | |
| 20 | Owyhee County | Very Low | 0.00 / yr | $5 | |
| 21 | Washington County | Very Low | 0.00 / yr | $5 | |
| 22 | Elmore County | Very Low | 0.00 / yr | $7 | |
| 23 | Gooding County | Very Low | 0.00 / yr | $4 | |
| 24 | Boise County | Very Low | 0.00 / yr | $3 | |
| 25 | Custer County | Very Low | 0.00 / yr | $1 | |
| 26 | Caribou County | Very Low | 0.00 / yr | $2 | |
| 27 | Camas County | Very Low | 0.00 / yr | $1 | |
| 28 | Bear Lake County | Very Low | 0.00 / yr | $1 | |
| 29 | Valley County | Very Low | 0.00 / yr | $1 | |
| 30 | Oneida County | Very Low | 0.00 / yr | $1 | |
| 31 | Clark County | Very Low | 0.00 / yr | $1 | |
| 32 | Franklin County | Very Low | 0.00 / yr | $1 | |
| 33 | Adams County | Very Low | 0.00 / yr | $0 | |
| 34 | Lemhi County | Very Low | 0.00 / yr | $0 |
34 Idaho counties with measurable volcanic activity risk. See the national volcanic activity ranking or all Idaho counties by overall risk.
Frequently Asked Questions
Which Idaho county has the highest volcanic activity risk?
Ada County has the highest FEMA volcanic activity risk score in Idaho at 74.3 (Very Low), with $235 in expected annual losses and about 0.00 events per year.
How many Idaho counties face significant volcanic activity risk?
34 Idaho counties record measurable volcanic activity risk in FEMA's National Risk Index; 0 of them are rated High or Very High.