Lemhi County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Lemhi County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every large fire

1. Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Volcanoes within 100 miles

1. U.S. volcanoes within 100 miles, from the USGS Volcano Hazards Program. The threat category is the USGS 2018 National Volcanic Threat Assessment, which ranks volcanoes by how hazardous their past eruptions were and how many people and how much infrastructure lie near them. It is not a forecast of eruption.

USGS Volcano Hazards Program, retrieved October 30, 2026.

Mapped landslides

Mapped by ID GS (356), USGS Conterminous (20), NASA (2).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Feb 8, 1996Flood, Western Lemhi County$44.0 million
   National Weather Service narrative

   Major flooding took place the second week of February in Northern Idaho. Conditions that developed in late January contributed significantly to the flood. Large amounts of low elevation snow fell during the third week of January, especially in Northern Idaho where valley locations reported 10 additional inches of snow with as much as 2 1/2 feet on the ground. During the last week in January temperatures dropped into the single digits for highs and 20 to 30 degrees below zero for lows, this resulted in ice buildup along many of the rivers.During the first week of Februray temperatures drastically warmed, but lows remained below freezing so snowmelt began slowly. Heavy rains also…

2. Dec 20, 2016High Wind, Eastern Lemhi County$500,000
   National Weather Service narrative

   Very strong winds caused a sale barn from the Lemhi County Fairgrounds to collapse during this event. A person who lives near the fairgrounds observed that the windows of his trailer home flexed during the high winds. No sensor was nearby to record the wind speed, but there is a sensor located to the west about a thousand feet above town that recorded a gust to 53 mph.

3. Aug 1, 2013Hail$490,000
   National Weather Service narrative

   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.

4. Jun 30, 2024Flash Flood$250,000
   National Weather Service narrative

   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.

5. Apr 24, 1996Flood, Western Lemhi County$100,000
   National Weather Service narrative

   Flooding took place in Northern Idaho due to rain and snow melt at the mid elevations. One and a half to two in half inches of rain fell in the Panhandle of Idaho causing the St. Joseph and Coeur d'Alene Rivers to rise above flood stage. Both rivers peaked on April 25th. Several structures that were being repaired from the February flood were washed out. From the Coeur d'Alene flooding Latour Creek Road was covered with three feet of water isolating seventy-five families. A farmer reported 30 head of cattle drowned along Latour creek behind the Cataldo Mission. At Kingston between Enaville and Cataldo, there was water over the road and some homes were flooded. In the Rose Lake…

6. Jun 19, 2025Thunderstorm Wind$70,000
   National Weather Service narrative

   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.

7. Sep 7, 2020High Wind, Eastern Lemhi County$60,000
   National Weather Service narrative

   Appropriately 40 mature Ponderosa pine and Douglas fir trees were blown down along 4th of July Creek Road northeast of Carmen. Several campers were trapped by the falling trees. In addition, around 20 cottonwood and aspen trees were either uprooted or had tops snapped out along Carmen Creek. Isolated tree damage was noted around Salmon. Power and phone outages occurred because of downed trees.

8. Jun 21, 2009Flood$50,000
   National Weather Service narrative

   Law enforcement reported three to four inches of water on portions of Highway 28 in areas between Lemhi and Leadore, with up to 12 inches of water flowing over Highway 28 near Lemhi. Precipitation amounts ranged between one to two inches in the area. Basement flooding and flooding of Macfarland Campground were reported.

9. Feb 6, 2015Flood$40,000
   National Weather Service narrative

   Temperatures up to 48 F on February 6th, 2015 and above-freezing temperatures near 44 F overnight led to rapid snow melt which caused Salmon, ID area creeks and rivers to rise rapidly on February 7th. Temperatures reached up to 56 F that day, with rain runoff further complicating issues. The main flooding occurred near Kitz Creek and its confluence with the Salmon River. Four homes sustained minor flood damage in Salmon, ID. Additionally, the Salmon County Airport was shutdown for the day due to water on the runway.

10. Jan 8, 2010Flood$20,000
    National Weather Service narrative

    Ice jam buildup on the Salmon River caused waters to rise and flood 4 to 8 miles north of Salmon near the Carmen area and flood homes. A camp ground on a gravel bar near the river was under water; the first time in two decades. The Morgan Bar recreation area was also submerged in water. Local county roads were flooded in the area.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

105°FJul 10, 1973

All-time low

−34°FJan 7, 1979

Warmest night

69°FJul 15, 2002

Coldest day

−11°FJan 7, 1979

Wettest day

1.60 inJul 26, 2017

Snowiest day

10.5 inJan 11, 2000

Hottest year

1981mean 48.1°F

Coldest year

2022mean 41.6°F

Wettest year

197714.75 in

Driest year

20214.73 in

Snowiest season

56.2 in1983-84

Station Salmon-ksra (USC00108080), 3,953 ft elevation, 3.2 miles from the population centre. Daily records from 1967 to October 26, 2026; 94.2% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00108080.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Volcanoes USGS Volcano Hazards Program, U.S. volcanoes and 2018 threat assessment.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.