24 flood insurance claims·$267,102 paid
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Lemhi County, Idaho. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding and river flooding driven by winter ice jams and seasonal storms define the flood risks in Lemhi County, Idaho. Over the last 30 years, the NOAA Storm Events Database recorded 16 flash flood events and 10 general flood events. Recent severe weather includes an ice jam related flood on the Lemhi River in January 2023 following extreme winter cold, and slow-moving thunderstorms that triggered debris flows in June 2023. Additionally, a combination of snowmelt and rain caused high flows in the Salmon River Basin in May 2017.
Federal flood insurance claims data shows impacts across multiple zones, with the highest claim volume concentrated in high-risk areas. Properties located in Zone A account for 14 claims with an average payout of $17,401 and an average recorded water depth of 27 inches. Additional claims occurred in Zone UNKNOWN with 5 claims averaging $7,628 and 2 inches of water depth, Zone X_UNSHADED with 3 claims averaging $11,873 and 1 inch of water depth, and Zone X with 2 claims averaging $43,083 and 3 inches of water depth. Homeowners, real estate agents, and journalists should pay the most attention to properties situated near rivers, streams, and low-lying areas subject to flash flooding, debris flows, and winter ice jams.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
In flood insurance claims here that reported a flood depth, the average was 16 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2017, with 3 claims and $81,090 paid.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
9 NOAA storm reports from Lemhi County describe what happened, in the words of the forecasters who covered it. Read the Idaho flood stories →
5 federal disaster declarations since 1984.
| Disaster | Began |
|---|---|
| Hurricane Katrina | Aug 29, 2005 |
| Wildfires | Jul 27, 2000 |
| Ice Jams And Flooding | Jan 17, 1984 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
26 since 1996: 16 flash floods and 10 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jun 30, 2024 | $250,000 |
| Flood | Jan 29, 2023 | — |
| Flash Flood | Jun 6, 2023 | — |
| Flash Flood | Aug 10, 2019 | — |
| Flood | May 31, 2017 | — |
| Flood | May 7, 2017 | — |
| Flood | Jun 1, 2017 | $10,000 |
| Flood | Feb 6, 2015 | $40,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jun 30, 2024. Flooding occurred along the Salmon River Road as brief but intense rainfall occurred.
Flood · Jan 29, 2023. Winter temperatures were the in the top 5 for coldest resulting in significant ice buildup on the Lemhi River. Cold temperatures culminated on January 30th with a low of -33F in Leadore and -18F in Salmon. Ice jam related flooding occurred around this significant cold period.
Flash Flood · Jun 6, 2023. Anomalous atmospheric moisture with slow moving thunderstorms triggered a few debris flows in Lemhi County.
Flash Flood · Aug 10, 2019. An evening severe thunderstorm brought damaging hail and flash flooding along Highway 95 in central Idaho. Another storm brought quarter-sized hail and a debris flow north of Salmon.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Lemhi County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.