Custer County, Montana
Natural disaster risk, federal disaster history and flood insurance facts.
Custer County, Montana has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 58% of US counties. It ranks 23rd of 56 counties in Montana. The costliest hazards here are cold waves, inland flooding and strong wind. FEMA estimates about $10 million a year in expected losses, or roughly $867 per resident. Since 2000 it has been included in 7 federal disaster or emergency declarations for natural events (5 major disasters). The most recent was in September 2020 (Snider/Rice Fire Complex). About 1 in 9 homes here carry federal flood insurance (687 policies). Since 1978, federal flood insurance has paid about $400,000 on 156 claims here.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Custer County
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Secure outdoor furniture and trash bins before storms.
- Have trees near the house checked.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Cold wave | 87.0 | $4M | ||
| Inland flooding | 38.3 | $4M | ||
| Strong wind | 60.6 | $575K | ||
| Wildfire | 85.4 | $550K | ||
| Lightning | 76.8 | $493K | ||
| Winter weather | 86.0 | $230K | ||
| Hail | 47.6 | $184K | ||
| Heat wave | 38.3 | $162K | ||
| Tornado | 16.2 | $126K | ||
| Earthquake | 31.4 | $68K | ||
| Drought | 26.9 | $13K | ||
| Ice storm | 10.0 | $4K | ||
| Landslide | 59.0 | $2K |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively high and community resilience is relatively low in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Custer County. 2020s bar runs to November 2026.
By type
Most recent
Montana also had 36 statewide declarations that did not name single counties.
Storm history since 1957
Tornado risk by county ›The National Weather Service has logged 540 storm reports in Custer County since 1957, with 2 deaths and 6 injuries and about $2.9 million in reported damage. The strongest on record here was an F2 tornado on July 11, 1965.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Jul 11, 1965 | F2 | – | 0 / 0 |
| Jun 25, 1975 | F2 | – | 0 / 0 |
| Jul 8, 2013 | EF1 | Ulmer | 0 / 0 |
| May 11, 1989 | F0 | – | 0 / 0 |
| Jun 24, 1991 | F0 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 20, 2011 | Flood | Knowlton | $1M |
| Jul 4, 1998 | Flash Flood | Miles City | $1M |
| May 11, 1989 | Tornado | – | $250K |
| Aug 7, 1995 | Thunderstorm Wind | Miles City | $180K |
| May 25, 2010 | Flood | Kinsey | $130K |
| Jul 18, 2010 | Thunderstorm Wind | Miles City | $60K |
Source: NOAA Storm Events Database, county-based reports through Jul 3, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Custer County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Custer County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 5,784 housing units.
Compare in Montana
All 56 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Yellowstone County | Inland flooding | |
| Gallatin County | Earthquake | |
| Missoula County | Inland flooding | |
| Flathead County | Inland flooding | |
| Cascade County | Inland flooding | |
| Lewis and Clark County | Cold wave | |
| Ravalli County | Wildfire | |
| Silver Bow County | Cold wave |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Rosebud County | 13 | |
| Fallon County | 6 | |
| Powder River County | 10 | |
| Carter County | 6 | |
| Garfield County | 10 | |
| Prairie County | 5 |
Common questions about Custer County
What is the biggest natural hazard in Custer County?
Cold wave has the highest expected yearly losses in Custer County, about $4.3 million a year in FEMA's estimate. Inland flooding is second at $3.5 million.
How many federal disasters has Custer County had?
Custer County has been included in 7 federal disaster or emergency declarations for natural events since 2000, including 5 major disasters. The most recent was Snider/Rice Fire Complex in September 2020.
Is Custer County a high-risk place to live?
Its overall rating is Very Low, 23rd highest of 56 in Montana. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Custer County?
Standard home insurance does not cover flooding. About 1 in 9 homes in Custer County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Custer County had?
NOAA records list 8 tornadoes in Custer County since 1950. The strongest was an F2 tornado on July 11, 1965. The weather service has also logged 239 hail reports and 30 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.