Minnehaha County, South Dakota

What hazards hit Minnehaha County most?

The most frequent records are hail reports: 504 since 1956. 50% of its hail reports since 1956 fell in May and June. The rank column places the county among South Dakota's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Minnehaha County had?

NOAA records 48 tornadoes in Minnehaha County from 1956 to 2026, the strongest rated F3, with 0 deaths and 4 injuries recorded in the county. That is 5th of 66 South Dakota counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 52 tornadoes whose track touched Minnehaha County since 1950 (NOAA's county records number 48: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.

Map of the strongest tornado tracks in South Dakota.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Minnehaha County?

The most recent record with damage, injuries or deaths is the January 19, 2025 cold/wind chill (1 death).

A deceased woman was found outdoors on January 19 just outside the city limits of Sioux Falls to the north of Family Park. Law enforcement noted the cause of death was exposure to the cold weather. Wind chill values throughout the day generally ranged from 10 to 30 below zero at the Sioux Falls Regional Airport (KFSD).
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1293929)

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Minnehaha County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

50% of its hail reports since 1956 fell in May and June. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Minnehaha County

FEMA's register lists 17 declarations that include Minnehaha County: 14 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for severe storm (8) and flood (5).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Minnehaha County had?

NOAA's Storm Events Database holds 230 flood or flash flood records for Minnehaha County from 1997 to 2026, on 133 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Minnehaha County ranks 577th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $8.9 million on 425 claims filed in Minnehaha County; the most in one year was 94 in 2010. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Minnehaha County

FEMA's National Risk Index rates Minnehaha County Relatively Moderate overall, with an expected annual loss of $104 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Minnehaha County

1. Minnehaha County 1,554
2. Lincoln County 959
3. Turner County 787
4. Lyon County, IA 774
5. McCook County 745
6. Rock County, MN 701
7. Pipestone County, MN 673
8. Lake County 664
9. Moody County 657

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in South DakotaEvery South Dakota tornado since 1950 and the counties with the most per square mile
• Hail in South DakotaThe state's hail reports, by county, year and month
• The South Dakota recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Minnehaha CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Minnehaha County's FEMA declarations (CSV)17 rows: every declaration that named the county, for your own analysis