Idaho Environment & Hazard Risk
0 counties rated high or very high risk. 11,153 storm events since 1996, #42 among states.
- Expected yearly loss
- $767M
- $418 per person
- Storm events since 1996
- 11,153
- Most often heavy snow
- Flood insurance policies
- 3,768
- $10.3M in claims paid
- Superfund sites
- 12
- 129 toxic release facilities
Risk by county
FEMA National Risk Index rating, highest risk first
| County | Overall risk | Top hazard | Flood policies | Flood claims paid |
|---|---|---|---|---|
| Ada County | Moderate | Winter weather | 1,541 | $499K |
| Bonneville County | Moderate | Landslide | 70 | $39.7K |
| Kootenai County | Low | Landslide | 209 | $746K |
| Idaho County | Low | Landslide | 10 | $9,891 |
| Bonner County | Low | Avalanche | 135 | $156K |
| Canyon County | Low | Winter weather | 350 | $102K |
| Bannock County | Low | Wildfire | 72 | $115K |
| Blaine County | Low | Avalanche | 377 | $3.9M |
| Shoshone County | Low | Landslide | 119 | $926K |
| Bingham County | Low | Winter weather | 88 | $99.5K |
| Madison County | Low | Lightning | 21 | $19.9K |
| Valley County | Low | Wildfire | 19 | - |
| Custer County | Low | Landslide | 17 | $1,902 |
| Elmore County | Low | Wildfire | 96 | $108K |
| Boise County | Low | Landslide | 24 | $35.6K |
| Twin Falls County | Low | Winter weather | 67 | $24.8K |
| Clearwater County | Low | Landslide | 9 | $36.5K |
| Owyhee County | Low | Wildfire | 3 | - |
| Cassia County | Low | Wildfire | 17 | $63.4K |
| Lemhi County | Very Low | Landslide | 31 | $267K |
| Jefferson County | Very Low | Winter weather | 35 | $116K |
| Adams County | Very Low | Wildfire | 10 | $9,389 |
| Fremont County | Very Low | Avalanche | 16 | $90.1K |
| Gem County | Very Low | Wildfire | 29 | $19.2K |
| Latah County | Very Low | Wildfire | 118 | $744K |
| Nez Perce County | Very Low | Wildfire | 27 | $30.6K |
| Washington County | Very Low | Wildfire | 54 | $991K |
| Teton County | Very Low | Avalanche | 42 | $25.5K |
| Boundary County | Very Low | Landslide | 10 | $8,395 |
| Gooding County | Very Low | Wildfire | 30 | $33.9K |
| Jerome County | Very Low | Wildfire | - | - |
| Minidoka County | Very Low | Winter weather | 10 | $187K |
| Benewah County | Very Low | Landslide | 49 | $618K |
| Payette County | Very Low | Wildfire | 25 | $247K |
| Power County | Very Low | Wildfire | - | - |
| Lincoln County | Very Low | Wildfire | 4 | $35.5K |
| Franklin County | Very Low | Wildfire | 4 | $2,525 |
| Caribou County | Very Low | Wildfire | 2 | $8,023 |
| Bear Lake County | Very Low | Avalanche | 1 | - |
| Camas County | Very Low | Avalanche | 5 | - |
| Butte County | Very Low | Avalanche | 6 | - |
| Lewis County | Very Low | Wildfire | 16 | - |
| Oneida County | Very Low | Wildfire | - | - |
| Clark County | Very Low | Avalanche | - | - |
Storm events by type
Since 1996: 126 deaths, $1.2B in property and crop damage
- Heavy Snow3,527 · 12 deaths
- Thunderstorm Wind2,127 · 11 deaths
- Winter Storm913 · 12 deaths
- Hail850 · 2 deaths
- High Wind796 · 4 deaths
- Flood468 · 1 death
- Wildfire435 · 6 deaths
- Winter Weather408 · 18 deaths
- Flash Flood324 · 2 deaths
- Heavy Rain262 · 1 death
- Funnel Cloud142
- Extreme Cold/Wind Chill133 · 1 death
Events per year
Most damaging storms
Since 2017, ranked by deaths, injuries and damage
- Heavy Snow01/18/2017
Lower Treasure Valley
$100M damage
What happened
Numerous reports from social media reported 6 to 9 inches of snow around Caldwell and 15 to 16 inches from Ontario to Payette and Weiser reported by emergency management. Significant damage occurred to agricultural buildings housing fresh produce.
- Thunderstorm Wind50 kt wind05/01/2021
(Muo)mountain Home a, Elmore County
3 deaths, 5 injured
What happened
The AWOS at Mountain Home AFB measured a 58 MPH wind gust with several reports of damage received by the public. A dust storm from the gust front of a nearby thunderstorm reduced visibility to near zero, resulting in a 7 car accident with 3 fatalities. Idaho State Police officials reported the accident was on Highway 51, southeast of Mountain Home. ISP officials have determined the dust storm reduced visibility significantly and was the cause of the accident.
- Avalanche01/07/2020
Central Panhandle Mountains
3 deaths, 2 injured
What happened
Broadcast media reported an Avalanche at the Silver Mountain Ski Resort.
- Hail2" hail04/08/2018
Idaho Falls, Bonneville County
$29.8M damage
What happened
At least 28 reports of 1 to 2 inch hail were reported in the Ammon and Idaho Falls area and extensive damage was reported to residential and business structures. Extensive automobile damage was reported as well. Emergency management and insurance company reports estimated the damage from the large hail at $29,750,000. Approximately 2,600 structures and 1,800 vehicles sustained damage from the hail storm.
- Wildfire08/03/2023
Central Panhandle Mountains
$24M damage
What happened
Ridge Creek Wildfire was started by unknown causes along the North of Trail 234 and on both sides of Hayden Creek 437 Road. It burned 4474 of timber and grass. No structures lost.
- Wildfire09/01/2023
Central Panhandle Mountains
$24M damage
What happened
Ridge Creek Wildfire was started by unknown causes along the North of Trail 234 and on both sides of Hayden Creek 437 Road. It burned 4474 of timber and grass. No structures lost.
Flood insurance
National Flood Insurance Program policies and claims
3,768 homes in Idaho have flood insurance, about 0.5% of residential buildings. In high-risk flood zones, 2,641 of 13,801 homes (19%) are insured.
- Flooding$2.5M · 111 claims
- Tropical Storm Hilary$0 · 1 claim
Drinking water
762 community water systems serve about 1,580,474 people
Since 2021, 183 systems reported 621 health-based violations. 226 systems had a violation of any kind still open at last report. These had the most:
- Mission Creek Water AssnServes 263 · Groundwater · Local government53 health violations+33 monitoring or reporting
- Meadow Lark Court LLCServes 45 · Groundwater · Private28 health violations+51 monitoring or reporting
- Bellevue City ofServes 2,747 · Groundwater · Local government22 health violations+8 monitoring or reporting
- Shotgun Cherokee Subd 5Serves 245 · Groundwater · Private17 health violations+128 monitoring or reporting
- Aspen Ridge SubdServes 204 · Groundwater · Private17 health violations+231 monitoring or reporting
- Cedar Springs Community WaterServes 130 · Groundwater · Private17 health violations+86 monitoring or reporting
- Meadows at West MountainServes 550 · Groundwater · Private16 health violations+20 monitoring or reporting
- Banida Water and Sewer DistServes 180 · Groundwater · Private16 health violations+89 monitoring or reporting
Select a county above to see every system that serves it.
Pollution sites
12 Superfund sites and 129 toxic release facilities
Superfund sites
- Blackbird MineProposed NPL Site, Lemhi County
- Bunker Hill Mining & Metallurgical ComplexFinal NPL Site, Smelterville
- Eastern Michaud Flats ContaminationFinal NPL Site, Pocatello
- Idaho National Engineering Laboratory (USDOE)Final NPL Site, Idaho Falls
- Kerr-Mcgee Chemical Corp. (Soda Springs Plant)Final NPL Site, Soda Springs
- Monsanto Chemical co. (Soda Springs Plant)Final NPL Site, Soda Springs
- Mountain Home Air Force BaseFinal NPL Site, Mountain Home
- Stibnite/Yellow Pine Mining AreaProposed NPL Site, Stibnite
Largest toxic releases
- Hecla Ltd Lucky Friday Mine Unit19.6 million lbs, Mullan
- Mccain Foods USA Inc.5.6 million lbs, Burley
- P4 Production LLC4.4 million lbs, Soda Springs
- U.S. Silver - Idaho Inc4.0 million lbs, Wallace
- US Ecology Idaho Inc.3.7 million lbs, Grand View
- J R Simplot Co Don Sid Ing3.0 million lbs, Pocatello
- Amalgamated Sugar Co2.3 million lbs, Paul
- Glanbia Foods Inc1.1 million lbs, Gooding
Facilities in Idaho reported 50.8 million lbs of toxic releases in 2024, 5.2 million lbs of it into the air.
Frequently asked questions
- What is the biggest natural hazard in Idaho?
- By expected annual loss, wildfire costs the most in Idaho ($143M a year), according to FEMA's National Risk Index.
- How many storms hit Idaho each year?
- NOAA recorded 11,153 storm events in Idaho since 1996, about 360 a year. The most common type is heavy snow.
- How many homes in Idaho have flood insurance?
- 3,768 residential flood insurance policies are in force in Idaho. Since 1978 the National Flood Insurance Program has paid $10.3M on 1,086 claims here.
- How many Superfund sites are in Idaho?
- Idaho has 12 Superfund sites on or deleted from EPA's National Priorities List.
Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.