Day County, South Dakota
Natural disaster risk, federal disaster history and flood insurance facts.
Day County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 72% of US counties. It ranks 26th of 66 counties in South Dakota. The costliest hazards here are cold waves, inland flooding and strong wind. FEMA estimates about $7.2 million a year in expected losses, or roughly $1,317 per resident. Since 1976 it has been included in 23 federal disaster or emergency declarations for natural events (21 major disasters). The most recent was in September 2026 (severe storms, straight-line winds, tornadoes and flooding). Only 12 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $4.2 million on 257 claims here, including $1.7 million for floods in 2011.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Day 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 | 76.0 | $2M | ||
| Inland flooding | 20.0 | $2M | ||
| Strong wind | 82.1 | $1M | ||
| Tornado | 40.6 | $695K | ||
| Hail | 69.0 | $416K | ||
| Wildfire | 77.9 | $259K | ||
| Ice storm | 76.1 | $243K | ||
| Winter weather | 85.1 | $217K | ||
| Heat wave | 23.2 | $65K | ||
| Earthquake | 14.7 | $12K | ||
| Lightning | 3.1 | $8K | ||
| Landslide | 42.1 | $599 | ||
| Drought | 13.6 | $126 |
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 very high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Day County. 2020s bar runs to November 2026.
By type
Most recent
Show all 23
South Dakota also had 46 statewide declarations that did not name single counties.
Storm history since 1953
Tornado risk by county ›The National Weather Service has logged 469 storm reports in Day County since 1953, with 0 deaths and 15 injuries and about $15.2 million in reported damage. The strongest on record here was an F2 tornado on July 17, 1996 near Pierpont.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Jul 17, 1996 | F2 | Pierpont | 0 / 0 |
| Jun 15, 1953 | F2 | – | 0 / 0 |
| Jun 19, 1979 | F1 | – | 0 / 0 |
| Jun 25, 1973 | F1 | – | 1 / 0 |
| Jun 11, 1954 | F1 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jun 1, 2019 | Flood | Pierpont | $12M |
| Jun 19, 1979 | Tornado | – | $3M |
| Jun 24, 1994 | Hail | – | $550K |
| Apr 12, 2023 | Flood | Pierpont | $300K |
| Jul 17, 1996 | Tornado | Pierpont | $200K |
| Apr 1, 2019 | Flood | Pierpont | $104K |
Source: NOAA Storm Events Database, county-based reports through Jul 30, 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 Day 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 Day 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; 3,440 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 |
|---|---|---|
| Brown County | 17 | |
| Codington County | 21 | |
| Roberts County | 22 | |
| Grant County | 20 | |
| Spink County | 21 | |
| Marshall County | 18 | |
| Clark County | 20 |
Common questions about Day County
What is the biggest natural hazard in Day County?
Cold wave has the highest expected yearly losses in Day County, about $2.2 million a year in FEMA's estimate. Inland flooding is second at $1.9 million.
How many federal disasters has Day County had?
Day County has been included in 23 federal disaster or emergency declarations for natural events since 1976, including 21 major disasters. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in September 2026.
Is Day County a high-risk place to live?
Its overall rating is Very Low, 26th 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 Day County?
Standard home insurance does not cover flooding. About 1 in 333 homes in Day 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 Day County had?
NOAA records list 33 tornadoes in Day County since 1950. The strongest was an F2 tornado on July 17, 1996 near Pierpont. The weather service has also logged 208 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.