Custer County, Montana: Natural Disaster Risk and History
Custer County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 42.1 out of 100, higher than about 42% of US counties, with cold waves, winter storms and wildfires scoring highest of its 18 hazards and $10 million a year in expected losses.
OpenFEMA lists 7 federal disaster declarations that included Custer County since 2000, not counting 2 for COVID-19; the latest is FM-5345-MT (Snider/Rice Fire Complex, declared 3 September 2020). NOAA's Storm Prediction Center recorded 10 tornadoes touching Custer County from 1950 to 2025.
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Population 11,841 Buildings worth $3.5 billion Area 3,832 sq mi Risk rank in Montana 23 of 56 FIPS 30017
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Cold wave | Relatively Moderate | 87.0 | $4.3 million | about 6.3 a year | 120 |
| Winter weather | Relatively High | 86.0 | $229,939 | about 16 a year | 300 |
| Wildfire | Relatively Low | 85.4 | $550,222 | about once every 189 years | — |
| Lightning | Relatively Moderate | 76.8 | $493,015 | about 31 a year | 47,479 strikes |
| Strong wind | Relatively Moderate | 60.6 | $575,081 | about once a year | 38 |
| Landslide | Very Low | 59.0 | $1,966 | about 2.9 a year | — |
| Hail | Relatively Low | 47.6 | $183,804 | about 1.8 a year | 68 |
| Inland flooding | Relatively Low | 38.3 | $3.5 million | about once every 1.1 years | 26 |
| Heat wave | Very Low | 38.3 | $161,907 | about 2.2 a year | 20 |
| Earthquake | Very Low | 31.4 | $67,637 | rarer than once in 1,000 years | — |
| Drought | Very Low | 26.9 | $12,815 | about 61 a year | 1,554 |
| Tornado | Very Low | 16.2 | $126,261 | about once every 3.8 years | 9 |
| Ice storm | Very Low | 10.0 | $3,963 | about once every 67 years | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| 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 7
Most common: Fire 2, Flood 2, Severe Storm 2, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 2000s | 3 | Severe Storm, Hurricane, Fire |
| 2010s | 3 | Flood ×2, Severe Storm |
| 2020s | 1 | Fire |
The last 7
Widest declarations that included Custer County
- Hurricane Katrina Evacuation (2005, EM-3253-MT): 56 Montana counties designated.
- Severe Storms and Flooding (2011, DR-1996-MT): 49 Montana counties designated.
- Wildfires (2000, DR-1340-MT): 48 Montana 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. Montana also had 18 statewide declarations with no county list.
Tornado record since 1950 10
| Tornadoes touching the county | 10 |
|---|---|
| Strongest-rated | (E)F2 ×3 |
| Peak month | July (4) |
| Deadliest | — |
| Longest path | 18 Jul 1962, F2, 40.6 mi path |
| Most recent | 31 May 2014, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 6 | 1 | 3 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 2 | 1 | 2 | 3 | 0 | 2 | 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 Custer County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Custer County (this page) | — | Very Low | 42.1 | Cold wave |
| Prairie County | 69 km | Very Low | 4.2 | Cold wave |
| Fallon County | 89 km | Very Low | 5.4 | Cold wave |
| Rosebud County | 89 km | Relatively Low | 49.7 | Wildfire |
| Powder River County | 96 km | Very Low | 4.0 | Wildfire |
| Carter County | 115 km | Very Low | 1.7 | Wildfire |
Nearest by distance between county centres. Every county in Montana, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 70.8 |
|---|---|
| Community resilience | Relatively Low 27.1 |
| Community risk factor | 1.35 |
| Expected annual loss, all hazards | $10 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 Custer County's main hazards
- Right now: National Weather Service alerts for Montana · all official warnings on Global Incident Tracker.
- Cold wave: Carbon monoxide in winter · Power outages now
- Winter weather: Power outages now · Carbon monoxide in winter
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- 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 Custer County
What natural disasters is Custer County, Montana most at risk from?
Custer County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 42.1 out of 100, higher than about 42% of US counties, with cold waves, winter storms and wildfires scoring highest of its 18 hazards and $10 million a year in expected losses.
How many federal disaster declarations has Custer County had?
OpenFEMA lists 7 federal disaster declarations that included Custer County since 2000, not counting 2 for COVID-19; the latest is FM-5345-MT (Snider/Rice Fire Complex, declared 3 September 2020). Another 18 Montana declarations were made statewide without a county list.
How many tornadoes have hit Custer County?
NOAA's Storm Prediction Center recorded 10 tornadoes touching Custer 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.