Heat Wave Risk in Idaho
All Idaho counties ranked by FEMA National Risk Index heat wave score
Heat Wave risk — prolonged periods of extreme heat that threaten health and infrastructure — is rated for 44 of 44 Idaho counties in FEMA's National Risk Index. Ada County carries the state's highest heat wave score at 92.9, with $7M in expected annual heat wave losses.
No Idaho county reaches the High band for heat wave, and expected annual losses from heat wave total roughly $33M statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Heat Wave
| # | County | Heat Wave Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | Ada County | Medium | 4.37 / yr | $7M | |
| 2 | Canyon County | Medium | 4.53 / yr | $3M | |
| 3 | Bingham County | Medium | 1.74 / yr | $2M | |
| 4 | Kootenai County | Medium | 3.31 / yr | $2M | |
| 5 | Twin Falls County | Medium | 3.23 / yr | $2M | |
| 6 | Bonneville County | Medium | 0.65 / yr | $2M | |
| 7 | Jefferson County | Medium | 1.94 / yr | $2M | |
| 8 | Bannock County | Medium | 2.07 / yr | $2M | |
| 9 | Madison County | Low | 1.24 / yr | $1M | |
| 10 | Jerome County | Low | 3.63 / yr | $789K | |
| 11 | Minidoka County | Low | 2.95 / yr | $1M | |
| 12 | Blaine County | Low | 1.72 / yr | $808K | |
| 13 | Elmore County | Low | 2.59 / yr | $704K | |
| 14 | Cassia County | Low | 2.49 / yr | $572K | |
| 15 | Gooding County | Low | 3.63 / yr | $487K | |
| 16 | Nez Perce County | Low | 4.52 / yr | $697K | |
| 17 | Bonner County | Low | 2.79 / yr | $424K | |
| 18 | Latah County | Low | 3.35 / yr | $492K | |
| 19 | Payette County | Low | 4.53 / yr | $428K | |
| 20 | Owyhee County | Low | 2.88 / yr | $208K | |
| 21 | Gem County | Low | 3.46 / yr | $284K | |
| 22 | Power County | Low | 2.41 / yr | $257K | |
| 23 | Lincoln County | Low | 2.94 / yr | $208K | |
| 24 | Washington County | Very Low | 3.11 / yr | $158K | |
| 25 | Idaho County | Very Low | 2.28 / yr | $165K | |
| 26 | Boundary County | Very Low | 2.79 / yr | $112K | |
| 27 | Shoshone County | Very Low | 2.89 / yr | $123K | |
| 28 | Fremont County | Very Low | 0.75 / yr | $177K | |
| 29 | Butte County | Very Low | 1.06 / yr | $110K | |
| 30 | Clearwater County | Very Low | 2.48 / yr | $80K | |
| 31 | Benewah County | Very Low | 3.20 / yr | $100K | |
| 32 | Franklin County | Very Low | 1.46 / yr | $147K | |
| 33 | Custer County | Very Low | 0.30 / yr | $40K | |
| 34 | Lewis County | Very Low | 3.68 / yr | $47K | |
| 35 | Adams County | Very Low | 1.69 / yr | $43K | |
| 36 | Valley County | Very Low | 1.00 / yr | $50K | |
| 37 | Oneida County | Very Low | 2.16 / yr | $61K | |
| 38 | Boise County | Very Low | 1.47 / yr | $36K | |
| 39 | Lemhi County | Very Low | 0.37 / yr | $23K | |
| 40 | Teton County | Very Low | 0.19 / yr | $21K | |
| 41 | Caribou County | Very Low | 0.36 / yr | $19K | |
| 42 | Camas County | Very Low | 1.33 / yr | $13K | |
| 43 | Bear Lake County | Very Low | 0.18 / yr | $9K | |
| 44 | Clark County | Very Low | 0.35 / yr | $7K |
44 Idaho counties with measurable heat wave risk. See the national heat wave ranking or all Idaho counties by overall risk.
Frequently Asked Questions
Which Idaho county has the highest heat wave risk?
Ada County has the highest FEMA heat wave risk score in Idaho at 92.9 (Medium), with $7M in expected annual losses and about 4.37 events per year.
How many Idaho counties face significant heat wave risk?
44 Idaho counties record measurable heat wave risk in FEMA's National Risk Index; 0 of them are rated High or Very High.