Lewis County, Idaho: Natural Disaster Risk and History
Lewis County, Idaho has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 3.1 out of 100, higher than about 3% of US counties, with wildfires, avalanches and landslides scoring highest of its 18 hazards and $2.0 million a year in expected losses.
OpenFEMA lists 10 federal disaster declarations that included Lewis County since 1964, not counting 2 for COVID-19; the latest is DR-4905-ID (Straight-Line Winds, declared 7 April 2026). NOAA's Storm Prediction Center recorded 1 tornado touching Lewis County from 1950 to 2025.
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Population 3,530 Buildings worth $1.4 billion Area 485 sq mi Risk rank in Idaho 42 of 44 FIPS 16061
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Wildfire | Relatively Low | 85.9 | $627,585 | about once every 151 years | — |
| Avalanche | Very Low | 62.7 | $1,616 | about once every 100 years | 0 |
| Landslide | Very Low | 39.5 | $519 | about once every 5.3 years | — |
| Earthquake | Very Low | 23.4 | $30,810 | about once every 725 years | — |
| Heat wave | Very Low | 19.3 | $47,166 | about 3.7 a year | 37 |
| Drought | Very Low | 15.3 | $608 | about 16 a year | 532 |
| Inland flooding | Very Low | 12.0 | $1.2 million | about once every 7.0 years | 4 |
| Cold wave | Very Low | 9.5 | $55,641 | about once every 3.8 years | 5 |
| Hail | Very Low | 8.6 | $20,285 | about once every 3.1 years | 12 |
| Tornado | Very Low | 2.8 | $4,964 | about once every 96 years | 1 |
| Winter weather | Very Low | 2.8 | $1,389 | about 2 a year | 379 |
| Strong wind | Very Low | 2.7 | $11,072 | about once every 5.4 years | 8 |
| Lightning | Very Low | 2.2 | $5,792 | about 19 a year | 14,177 strikes |
| Ice storm | Very Low | 1.2 | $419 | about once every 67 years | 0 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 10
Most common: Flood 3, Fire 3, Severe Storm 2, Straight-Line Winds 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 2 | Fire, Flood |
| 1990s | 1 | Severe Storm |
| 2000s | 2 | Hurricane, Fire |
| 2010s | 3 | Flood, Fire, Severe Storm |
| 2020s | 2 | Straight-Line Winds, Flood |
The last 10
Widest declarations that included Lewis County
- Hurricane Katrina (2005, EM-3244-ID): 44 Idaho counties designated.
- Heavy Rains & Flooding (1964, DR-186-ID): 27 Idaho counties designated.
- Wildfires (2000, DR-1341-ID): 15 Idaho counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Idaho also had 8 statewide declarations with no county list.
Tornado record since 1950 1
| Tornadoes touching the county | 1 |
|---|---|
| Strongest-rated | (E)F0 ×1 |
| Peak month | October (1) |
| Deadliest | — |
| Longest path | 7 Oct 2010, EF0, 0.4 mi path |
| Most recent | 7 Oct 2010, EF0, 0.4 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Lewis County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Lewis County (this page) | — | Very Low | 3.1 | Wildfire |
| Nez Perce County | 27 km | Very Low | 33.0 | Wildfire |
| Asotin County, WA | 60 km | Very Low | 17.9 | Wildfire |
| Latah County | 68 km | Very Low | 33.3 | Wildfire |
| Clearwater County | 76 km | Relatively Low | 46.9 | Landslide |
| Idaho County | 86 km | Relatively Low | 78.4 | Landslide |
Nearest by distance between county centres. Every county in Idaho, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 60.8 |
|---|---|
| Community resilience | Very Low 3.4 |
| Community risk factor | 1.29 |
| Expected annual loss, all hazards | $2.0 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Lewis County's main hazards
- Right now: National Weather Service alerts for Idaho · all official warnings on Global Incident Tracker.
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Avalanche: Official warnings now
- Landslide: Landslides recorded
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets 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).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. 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).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Lewis County
What natural disasters is Lewis County, Idaho most at risk from?
Lewis County, Idaho has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 3.1 out of 100, higher than about 3% of US counties, with wildfires, avalanches and landslides scoring highest of its 18 hazards and $2.0 million a year in expected losses.
How many federal disaster declarations has Lewis County had?
OpenFEMA lists 10 federal disaster declarations that included Lewis County since 1964, not counting 2 for COVID-19; the latest is DR-4905-ID (Straight-Line Winds, declared 7 April 2026). Another 8 Idaho declarations were made statewide without a county list.
How many tornadoes have hit Lewis County?
NOAA's Storm Prediction Center recorded 1 tornado touching Lewis County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.