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Bonneville County, Idaho

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively Moderate overall risk
2nd of 44highest risk in Idaho
$65Mexpected losses a year
5federal declarations
1 in 500homes with flood insurance
Photo: U.S. Geological Survey, public domain

Bonneville County, Idaho has a moderate overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 82% of US counties. It ranks 2nd of 44 counties in Idaho. The costliest hazards here are inland flooding, earthquakes and cold waves. FEMA estimates about $65 million a year in expected losses, or roughly $522 per resident. Since 1964 it has been included in 5 federal disaster or emergency declarations for natural events (3 major disasters). The most recent was in August 2016 (Henrys Creek Fire). Fewer than 1 in 100 homes here carry federal flood insurance (70 policies). Since 1978, federal flood insurance has paid about $40,000 on 17 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Bonneville County

$24.3 million a yearExpected losses. Damaging events about once every 2 years.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.

Earthquake

Moderate
$16.1 million a yearExpected losses. Damaging events about once every 30 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
$12.1 million a yearExpected losses. Damaging events about once a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
HazardRatingScoreExpected loss a year
Inland floodingModerate78.6
$24M
EarthquakeModerate94.2
$16M
Cold waveHigh93.0
$12M
AvalancheHigh94.2
$4M
Heat waveModerate81.2
$2M
WildfireModerate90.3
$2M
HailModerate84.9
$2M
LightningHigh89.5
$2M
Strong windLow43.9
$612K
TornadoVery Low16.2
$217K
Winter weatherModerate66.2
$150K
LandslideModerate94.2
$142K
Ice stormVery Low26.8
$35K
DroughtVery Low19.4
$5K
Volcanic activityVery Low72.3
$163

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Bonneville County. 2020s bar runs to November 2026.

By type

Flood2
Severe Storm1
Hurricane1
Fire1

Most recent

Aug 25, 2016Henrys Creek FireFire management
Sep 13, 2005Hurricane KatrinaEmergency
Jun 13, 1997Severe Storms, Snowmelt, Land/Mud Slides, FloodingMajor disaster
Jun 6, 1976Dam Collapse, FloodingMajor disaster
Dec 31, 1964Heavy Rains & FloodingMajor disaster

Idaho also had 16 statewide declarations that did not name single counties.

Storm history since 1956

Tornado risk by county ›

The National Weather Service has logged 224 storm reports in Bonneville County since 1956, with 1 death and 9 injuries and about $40.7 million in reported damage. The strongest on record here was an F2 tornado on April 7, 1978.

6tornadoes
44hail reports, largest 2.75 inches
137damaging thunderstorm winds
20floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Apr 7, 1978F2–1 / 0
Feb 14, 2000F1Cotton0 / 0
Apr 21, 1981F1–0 / 0
May 24, 1989F0–0 / 0
Nov 17, 2017EF0Iona0 / 0

Most damaging storms

DateTypeNearDamage
Apr 7, 2018HailIdaho Falls$30M
Aug 1, 2014Heavy RainIdaho Falls$6M
Apr 7, 1978Tornado–$3M
Jul 2, 2022LightningIona$800K
May 23, 2023Flash FloodIdaho Falls$800K
Feb 5, 2017FloodUcon$250K

Source: NOAA Storm Events Database, county-based reports through Jul 25, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Bonneville County

Check your address flood zone ›
0.2%of homes have federal flood insurance (70 policies)
0%of homes in mapped high-risk flood zones are insured
$39,668paid on 17 flood claims since 1978
1997costliest year, with $35,049 paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Bonneville County

$368,800median home value (Idaho $418,600, US $332,700)
1985median year homes were built (Idaho 1991, US 1980)
45%of homes built before 1980, before many modern wind, quake and flood building rules
4.2%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 47,489 housing units.

Compare in Idaho

All 44 ›
Largest countiesOverall riskTop hazard
Ada CountyModerateInland flooding
Canyon CountyLowInland flooding
Kootenai CountyLowInland flooding
Bonneville CountyModerateInland flooding
Twin Falls CountyLowInland flooding
Bannock CountyLowWildfire
Madison CountyLowInland flooding
Bingham CountyLowInland flooding

Neighboring counties

CountyOverall riskDeclarations
Madison CountyLow3
Bingham CountyLow5
Jefferson CountyVery Low4
Teton County, WYLow3
Lincoln County, WYLow3
Teton CountyVery Low1
Caribou CountyVery Low3

Cities in Bonneville County

Common questions about Bonneville County

What is the biggest natural hazard in Bonneville County?

Inland flooding has the highest expected yearly losses in Bonneville County, about $24.3 million a year in FEMA's estimate. Earthquake is second at $16.1 million.

How many federal disasters has Bonneville County had?

Bonneville County has been included in 5 federal disaster or emergency declarations for natural events since 1964, including 3 major disasters. The most recent was Henrys Creek Fire in August 2016.

Is Bonneville County a high-risk place to live?

Its overall rating is Relatively Moderate, 2nd highest of 44 in Idaho. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Bonneville County?

Standard home insurance does not cover flooding. About 1 in 500 homes in Bonneville County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Bonneville County had?

NOAA records list 6 tornadoes in Bonneville County since 1950. The strongest was an F2 tornado on April 7, 1978. The weather service has also logged 44 hail reports and 20 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.