Custer County, South Dakota
Natural disaster risk, federal disaster history and flood insurance facts.
Custer County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 84% of US counties. It ranks 37th of 66 counties in South Dakota. The costliest hazards here are wildfires, inland flooding and cold waves. FEMA estimates about $8.8 million a year in expected losses, or roughly $1,056 per resident. Since 1972 it has been included in 15 federal disaster or emergency declarations for natural events (8 major disasters). The most recent was in April 2026 (straight-line winds). Only 44 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $646,000 on 50 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
- Clear dry plants and debris within 5 feet of the house.
- Get home insurance quotes early; availability varies by area.
- 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.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Wildfire | 94.2 | $4M | ||
| Inland flooding | 19.3 | $3M | ||
| Cold wave | 23.3 | $399K | ||
| Tornado | 22.1 | $396K | ||
| Hail | 44.1 | $292K | ||
| Strong wind | 15.6 | $185K | ||
| Winter weather | 60.2 | $127K | ||
| Lightning | 24.9 | $123K | ||
| Earthquake | 25.1 | $63K | ||
| Heat wave | 5.1 | $8K | ||
| Landslide | 52.1 | $2K | ||
| Ice storm | 3.0 | $2K | ||
| Drought | 16.2 | $2K | ||
| Avalanche | 2.5 | $1 |
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 very low and community resilience is relatively moderate 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
Show all 15
South Dakota also had 46 statewide declarations that did not name single counties.
Storm history since 1955
Tornado risk by county ›The National Weather Service has logged 998 storm reports in Custer County since 1955, with 0 deaths and 2 injuries and about $9.9 million in reported damage. The strongest on record here was an F2 tornado on June 22, 1966.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Jun 22, 1966 | F2 | – | 0 / 0 |
| Jun 22, 1961 | F2 | – | 0 / 0 |
| Jun 11, 1965 | F2 | – | 0 / 0 |
| Jul 15, 1969 | F1 | – | 0 / 0 |
| Jun 7, 2012 | EF1 | Argyle | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Aug 17, 2007 | Flash Flood | Hermosa | $3M |
| Sep 4, 2013 | Hail | Custer | $2M |
| Aug 2, 2019 | Flash Flood | Custer | $1M |
| Aug 1, 2001 | Lightning | Custer | $500K |
| Aug 7, 2011 | Hail | Hermosa | $400K |
| Jul 8, 2013 | Hail | Hermosa | $400K |
Source: NOAA Storm Events Database, county-based reports through Jul 31, 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; 5,291 housing units.
Compare in South Dakota
All 66 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Minnehaha County | Tornado | |
| Pennington County | Inland flooding | |
| Lincoln County | Tornado | |
| Brown County | Cold wave | |
| Brookings County | Inland flooding | |
| Meade County | Inland flooding | |
| Codington County | Inland flooding | |
| Lawrence County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Pennington County | 19 | |
| Oglala Lakota County | 14 | |
| Fall River County | 14 | |
| Weston County, WY | 5 | |
| Niobrara County, WY | 3 |
Common questions about Custer County
What is the biggest natural hazard in Custer County?
Wildfire has the highest expected yearly losses in Custer County, about $4 million a year in FEMA's estimate. Inland flooding is second at $3.2 million.
How many federal disasters has Custer County had?
Custer County has been included in 15 federal disaster or emergency declarations for natural events since 1972, including 8 major disasters. The most recent was Straight-Line Winds in April 2026.
Is Custer County a high-risk place to live?
Its overall rating is Very Low, 37th highest of 66 in South Dakota. 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 125 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 14 tornadoes in Custer County since 1950. The strongest was an F2 tornado on June 22, 1966. The weather service has also logged 697 hail reports and 38 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.