Walworth County, South Dakota severe weather history spans 410 recorded events between 1955 and 2026. The dominant hazard is thunderstorm wind, accounting for 45.6% of all recorded events. It ranks #1,217 nationally and #39 in South Dakota.
410
Recorded events
0
Direct deaths
2
Direct injuries
$3.9M
Property damage
The record
What the Walworth County, South Dakota severe weather history record shows
Across the archive, Walworth County, South Dakota severe weather history averages 5.8 recorded events a year. The busiest stretch on record is the 2010s, with 162 events logged in that decade alone. Roughly 58 events fall before 1990 and 352 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The costliest is flash flood, with $3.0M in reported property damage. In total, 6 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Walworth County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 187 | 0 | $51K | 87 | 1960–2026 |
| Hail | 177 | 0 | $0 | 3 | 1963–2025 |
| Tornado | 28 | 0 | $578K | F3 | 1955–2025 |
| Flash Flood | 8 | 0 | $3.0M | 0 | 1997–2018 |
| Flood | 7 | 0 | $292K | 0 | 2007–2019 |
| Funnel Cloud | 3 | 0 | $0 | 0 | 2009–2020 |
Decade by decade
Walworth County, South Dakota severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
30 mapped tornado paths intersect this county: 28 touched down inside it and 2 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2010-05-22 | EF4 | 0 | 0 | 5.7 mi | Touched down here |
| 1968-06-20 | EF3 | 0 | 0 | 8.8 mi | Touched down here |
| 1968-06-20 | EF3 | 0 | 0 | 0.1 mi | Touched down here |
| 1964-06-18 | EF2 | 0 | 2 | 24.6 mi | Crossed in |
| 1961-06-28 | EF2 | 0 | 0 | 1.0 mi | Touched down here |
| 1959-07-03 | EF2 | 0 | 0 | 0.1 mi | Touched down here |
| 1955-04-19 | EF2 | 0 | 0 | 18.2 mi | Crossed in |
| 2025-09-14 | EF1 | 0 | 0 | 4.0 mi | Touched down here |
| 2010-05-22 | EF1 | 0 | 0 | 0.5 mi | Touched down here |
| 1986-08-06 | EF1 | 0 | 0 | 1.5 mi | Touched down here |
Significant events
Deadliest events on record in Walworth County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jun 18, 1964 | Tornado | 0 | 2 | $25K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
The tornado tracked north-northwest over mainly open country near the city of Mobridge. This tornado initially hit a farmstead where damage was observed to a grain silo. It then tipped two semi-trailers on SD Highway 1804. The tornado destroyed an outbuilding at another farmstead located a mile south of US Highway 12. As the tornado crossed US Highway 12, it overturned a camper being pulled by a vehicle and bent a power pole. After crossing US Highway 12, the tornado tracked just west of 290th Avenue, taking down a series of six power poles that were either completely broken or severely bent before the tornado dissipated.
In Mobridge, powerful thunderstorm winds broke three power poles. The roof of a business, which had been previously damaged, was completely ripped off. The nearby Automated Surface Observing System at the Mobridge Regional Airport reported a gust of 61 mph.
Golf ball to baseball size hail along with severe winds brought a destructive path of crops from northwest of Java to Java during the evening hours. The path width was anywhere from 2 to 5 miles. The destruction was shown on satellite.
Context
Risk, population and federal disasters
Very Low
FEMA NRI risk rating
5,271
Population (ACS)
$137K
Median home value
12
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 5, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Sep 23, 2019 | Flood | SEVERE STORMS AND FLOODING | DR |
| Jun 7, 2019 | Flood | SEVERE WINTER STORM, SNOWSTORM, AND FLOODING | DR |
| Mar 10, 2010 | Severe Storm | SEVERE WINTER STORM | DR |
| Sep 10, 2005 | Coastal Storm | HURRICANE KATRINA EVACUATION | EM |
Quick answers
Frequently asked
How many severe weather events have been recorded in Walworth County, South Dakota?
410 events are on record between 1955 and 2026, causing 0 direct deaths and $3.9M in property damage.
What is the most common severe weather hazard in Walworth County?
Thunderstorm Wind, with 187 recorded events — 45.6% of everything in the archive for this county.
How many tornadoes have crossed Walworth County?
30 mapped tornado paths intersect the county boundary; 28 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Walworth County?
12 federal disaster declarations from FEMA include Walworth County, each tied to a specific incident period.
How risky is Walworth County compared with the rest of the country?
FEMA's National Risk Index rates Walworth County as very low risk, placing it in the 40 percentile of its state for expected annual loss.
Where does the Walworth County, South Dakota severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Union County 491
- Turner County 423
- Tripp County 595
- Yankton County 531
- Todd County 567
- Ziebach County 489
Cite this page
“Walworth County, South Dakota.” Severe Weather History. severeweatherhistory.com/county/south-dakota/walworth-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.