Lemhi County, Idaho severe weather history spans 135 recorded events between 1956 and 2026. The dominant hazard is thunderstorm wind, accounting for 42.2% of all recorded events. It ranks #2,759 nationally and #12 in Idaho.
135
Recorded events
3
Direct deaths
2
Direct injuries
$1.3M
Property damage
The record
What the Lemhi County, Idaho severe weather history record shows
Across the archive, Lemhi County, Idaho severe weather history averages 1.9 recorded events a year. The busiest stretch on record is the 2000s, with 49 events logged in that decade alone. Roughly 14 events fall before 1990 and 121 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Lemhi County, Idaho record is wildfire, responsible for 2 direct deaths. The costliest is hail, with $509K in reported property damage. In total, 10 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Lemhi County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 57 | 0 | $147K | 76 | 1976–2025 |
| Hail | 32 | 0 | $509K | 1.75 | 1966–2024 |
| Flash Flood | 16 | 0 | $275K | 0 | 2003–2024 |
| Heavy Rain | 8 | 0 | $0 | 0 | 2004–2014 |
| Flood | 8 | 0 | $120K | 0 | 2009–2026 |
| Debris Flow | 6 | 0 | $5K | 0 | 2021–2023 |
| Tornado | 3 | 0 | $253K | F1 | 1956–1987 |
| Lightning | 2 | 1 | $0 | 0 | 1998–2010 |
| Wildfire | 2 | 2 | $0 | 0 | 2000–2003 |
| Funnel Cloud | 1 | 0 | $0 | 0 | 2009–2009 |
Decade by decade
Lemhi County, Idaho severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
3 mapped tornado paths intersect this county: 3 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1987-06-15 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1984-08-24 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1956-06-01 | EF1 | 0 | 0 | 0.5 mi | Touched down here |
Significant events
Deadliest events on record in Lemhi County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jul 22, 2003 | Wildfire | SHOUP | 2 | 0 | $0 |
| Aug 10, 2010 | Lightning | CARMEN | 1 | 0 | $0 |
| Jun 26, 1998 | Lightning | LEADORE | 0 | 2 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
A very large right-moving & long-lived supercell developed across south-central Idaho and tracked north and east across northeastern Lemhi county. A trained spotter in Salmon, Idaho reported quarter size hail. Insurance companies reported at least 200 damage claims to both vehicles and homes from downtown, northwest Salmon and between Salmon and Carmen. An auto body reported fixing 15 passenger vehicles and 20 recreation vehicles caused by hail damage. The hail fell for at least 15 minutes damaging roofs, siding, stucco and windows. One person reported this was the worst storm she had seen in 42 years.
Flash flooding and mudslides occurred along Salmon River Road from just above Ebenezer Campground to just below Owl Creek. Radar estimates of up to 1.25 inches of rain fell over a half hour period across the southern half of the Owl Creek Basin. There were three major slides along the Salmon River Road, near Poverty Flat, Skull Gulch, and one roughly 0.3 miles in length where the road bank collapsed into the river. The Skull Gulch slide destroyed at least one outbuilding. There were also 30 to 50 additional small slides across the Salmon River Road that didn't cause structural damage.
Destructive thunderstorms swept through the Leadore area, unleashing estimated wind gusts of 80 mph. A local motel and a double-wide mobile home had their roofs ripped off by the violent winds. The storm also toppled trees, damaged home siding, pushed over 300 feet of fencing, and rolled a 300-gallon fuel tank.
Context
Risk, population and federal disasters
Very Low
FEMA NRI risk rating
8,249
Population (ACS)
$326K
Median home value
5
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 9, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Sep 13, 2005 | Hurricane | HURRICANE KATRINA | EM |
| Sep 1, 2000 | Fire | WILDFIRES | DR |
| Feb 16, 1984 | Snowstorm | ICE JAMS AND FLOODING | DR |
Quick answers
Frequently asked
How many severe weather events have been recorded in Lemhi County, Idaho?
135 events are on record between 1956 and 2026, causing 3 direct deaths and $1.3M in property damage.
What is the most common severe weather hazard in Lemhi County?
Thunderstorm Wind, with 57 recorded events — 42.2% of everything in the archive for this county.
How many tornadoes have crossed Lemhi County?
3 mapped tornado paths intersect the county boundary; 3 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Lemhi County?
5 federal disaster declarations from FEMA include Lemhi County, each tied to a specific incident period.
How risky is Lemhi County compared with the rest of the country?
FEMA's National Risk Index rates Lemhi County as very low risk, placing it in the 41 percentile of its state for expected annual loss.
Where does the Lemhi County, Idaho severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Latah County 99
- Lewis County 51
- Kootenai County 134
- Lincoln County 81
- Jerome County 51
- Madison County 112
Cite this page
“Lemhi County, Idaho.” Severe Weather History. severeweatherhistory.com/county/idaho/lemhi-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.