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Jefferson County, Idaho

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

Very Low overall risk
21st of 44highest risk in Idaho
$17Mexpected losses a year
4federal declarations
1 in 333homes with flood insurance
Photo: U.S. Geological Survey, public domain

Jefferson County, Idaho has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 60% of US counties. It ranks 21st of 44 counties in Idaho. The costliest hazards here are inland flooding, cold waves and earthquakes. FEMA estimates about $17 million a year in expected losses, or roughly $558 per resident. Since 1976 it has been included in 4 federal disaster or emergency declarations for natural events (3 major disasters). The most recent was in April 2017 (severe winter storms and flooding). Only 35 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $116,000 on 18 claims here.

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

Top risks in Jefferson County

$6 million a yearExpected losses. Damaging events about once every 3 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.

Cold wave

Moderate
$5.6 million a yearExpected losses. Damaging events about 3 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$2.4 million a yearExpected losses. Damaging events about once every 85 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
HazardRatingScoreExpected loss a year
Inland floodingLow37.1
$6M
Cold waveModerate81.8
$6M
EarthquakeLow80.6
$2M
Heat waveModerate79.1
$2M
LightningLow54.7
$381K
Winter weatherModerate82.7
$329K
WildfireVery Low62.5
$138K
Strong windVery Low12.4
$133K
HailVery Low20.6
$100K
TornadoVery Low7.0
$47K
DroughtVery Low22.2
$9K
Ice stormVery Low10.9
$8K
LandslideVery Low34.5
$596
Volcanic activityVery Low58.3
$37
AvalancheVery Low1.9
$0

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 relatively low in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Flood2
Severe Storm1
Hurricane1

Most recent

Apr 21, 2017Severe Winter Storms and FloodingMajor disaster
Sep 13, 2005Hurricane KatrinaEmergency
Jun 13, 1997Severe Storms, Snowmelt, Land/Mud Slides, FloodingMajor disaster
Jun 6, 1976Dam Collapse, FloodingMajor disaster

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

Storm history since 1964

Tornado risk by county ›

The National Weather Service has logged 242 storm reports in Jefferson County since 1964, with 0 deaths and 1 injury and about $8.6 million in reported damage. The strongest on record here was an F1 tornado on June 1, 2002 near Roberts.

18tornadoes
29hail reports, largest 1.75 inches
181damaging thunderstorm winds
11floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Jun 1, 2002F1Roberts0 / 0
Jul 8, 1980F1–0 / 0
Jun 4, 1991F1–0 / 0
Jun 2, 1992F1–0 / 0
Apr 11, 1985F1–0 / 0

Most damaging storms

DateTypeNearDamage
Aug 1, 2014Heavy RainMonteview$4M
Feb 5, 2017FloodCamas$2M
Jan 18, 2000Thunderstorm WindCountywide$560K
Mar 1, 2017FloodCamas$435K
Jul 18, 2000Thunderstorm WindCountywide$360K
Apr 9, 2023FloodRoberts$127K

Source: NOAA Storm Events Database, county-based reports through May 13, 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 Jefferson County

Check your address flood zone ›
0.3%of homes have federal flood insurance (35 policies)
5.8%of homes in mapped high-risk flood zones are insured
$115,665paid on 18 flood claims since 1978
1997costliest year, with $94,213 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 Jefferson County

$408,400median home value (Idaho $418,600, US $332,700)
1994median year homes were built (Idaho 1991, US 1980)
41%of homes built before 1980, before many modern wind, quake and flood building rules
7.2%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; 10,779 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
Bonneville CountyModerate5
Madison CountyLow3
Bingham CountyLow5
Fremont CountyVery Low3
Butte CountyVery Low4
Clark CountyVery Low2

Common questions about Jefferson County

What is the biggest natural hazard in Jefferson County?

Inland flooding has the highest expected yearly losses in Jefferson County, about $6 million a year in FEMA's estimate. Cold wave is second at $5.6 million.

How many federal disasters has Jefferson County had?

Jefferson County has been included in 4 federal disaster or emergency declarations for natural events since 1976, including 3 major disasters. The most recent was Severe Winter Storms and Flooding in April 2017.

Is Jefferson County a high-risk place to live?

Its overall rating is Very Low, 21st 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 Jefferson County?

Standard home insurance does not cover flooding. About 1 in 333 homes in Jefferson 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 Jefferson County had?

NOAA records list 18 tornadoes in Jefferson County since 1950. The strongest was an F1 tornado on June 1, 2002 near Roberts. The weather service has also logged 29 hail reports and 11 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.