Brown County, South Dakota severe weather history spans 1,102 recorded events between 1955 and 2025. The dominant hazard is hail, accounting for 39.7% of all recorded events. It ranks #103 nationally and #4 in South Dakota.
1,102
Recorded events
4
Direct deaths
33
Direct injuries
$10.6M
Property damage
The record
What the Brown County, South Dakota severe weather history record shows
Across the archive, Brown County, South Dakota severe weather history averages 15.7 recorded events a year. The busiest stretch on record is the 2010s, with 306 events logged in that decade alone. Roughly 198 events fall before 1990 and 904 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Brown County, South Dakota record is thunderstorm wind, responsible for 2 direct deaths. The costliest is flash flood, with $5.2M in reported property damage. In total, 8 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Brown County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 437 | 0 | $6K | 4.5 | 1959–2025 |
| Thunderstorm Wind | 404 | 2 | $6K | 113 | 1955–2025 |
| Flood | 140 | 0 | $1.2M | 0 | 2007–2025 |
| Tornado | 84 | 2 | $4.2M | F4 | 1955–2025 |
| Flash Flood | 22 | 0 | $5.2M | 0 | 1999–2025 |
| Funnel Cloud | 9 | 0 | $0 | 0 | 2008–2025 |
| Wildfire | 5 | 0 | $0 | 0 | 1999–2003 |
| Lightning | 1 | 0 | $2K | 0 | 2014–2014 |
Decade by decade
Brown 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
84 mapped tornado paths intersect this county: 81 touched down inside it and 3 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2002-06-23 | EF4 | 0 | 0 | 9.0 mi | Touched down here |
| 1973-07-01 | EF3 | 1 | 3 | 0.3 mi | Touched down here |
| 1961-06-21 | EF3 | 1 | 7 | 156.3 mi | Touched down here |
| 2002-06-23 | EF3 | 0 | 0 | 10.0 mi | Touched down here |
| 1996-05-31 | EF3 | 0 | 1 | 32.0 mi | Touched down here |
| 1969-06-25 | EF3 | 0 | 6 | 1.5 mi | Touched down here |
| 1965-05-20 | EF3 | 0 | 0 | 3.8 mi | Touched down here |
| 1966-07-31 | EF2 | 1 | 3 | 2.3 mi | Touched down here |
| 2010-05-22 | EF2 | 0 | 0 | 18.6 mi | Crossed in |
| 2010-05-22 | EF2 | 0 | 0 | 1.3 mi | Touched down here |
Significant events
Deadliest events on record in Brown County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Sep 25, 1986 | Thunderstorm Wind | 2 | 5 | $0 | |
| Jul 1, 1973 | Tornado | 1 | 3 | $25K | |
| Aug 1, 1966 | Tornado | 1 | 3 | $250K | |
| Jun 16, 1978 | Tornado | 0 | 15 | $250K | |
| Jun 25, 1969 | Tornado | 0 | 6 | $250K | |
| May 31, 1996 | Tornado | ABERDEEN | 0 | 1 | $750K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Slow moving thunderstorms brought very heavy rains of 2 to 4 inches in and around Aberdeen causing extensive road flooding throughout the city. Dozens of basements were flooded and damaged along with some sewer backups. Many vehicles became stalled with the police sent out to direct traffic. There were also some power outages.
Numerous county roads and area fields were overrun with flowing water. The level of Richmond Lake rose nearly a foot a day after the event from high inflows. This rapid rise in the lake level resulted in numerous boat and fishing docks being submerged. Several boats were also trapped under lift canopies due to the high water. There were reports of several boats breaking free of their mooring and floating toward the spillway.
A severe hailstorm with hail up to baseball size damaged a home and at least 160 acres of wheat and corn seven miles west of Barnard. Windows were knocked out on several other homes and farm buildings in the area. Most of the hail was from 0.75 to 1.75 of an inch in diameter.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
37,877
Population (ACS)
$221K
Median home value
19
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Jul 6, 2023 | Flood | FLOODING | DR |
| Apr 5, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Jun 7, 2019 | Flood | SEVERE WINTER STORM, SNOWSTORM, AND FLOODING | DR |
| May 13, 2011 | Flood | FLOODING | DR |
| May 13, 2010 | Flood | FLOODING | DR |
Within the county
Most affected places
- Hecla 189
- Aberdeen 161
- Columbia 135
- Frederick 101
Quick answers
Frequently asked
How many severe weather events have been recorded in Brown County, South Dakota?
1,102 events are on record between 1955 and 2025, causing 4 direct deaths and $10.6M in property damage.
What is the most common severe weather hazard in Brown County?
Hail, with 437 recorded events — 39.7% of everything in the archive for this county.
How many tornadoes have crossed Brown County?
84 mapped tornado paths intersect the county boundary; 81 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Brown County?
19 federal disaster declarations from FEMA include Brown County, each tied to a specific incident period.
How risky is Brown County compared with the rest of the country?
FEMA's National Risk Index rates Brown County as relatively low risk, placing it in the 74 percentile of its state for expected annual loss.
Where does the Brown 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
- Brookings County 509
- Brule County 385
- Bon Homme County 479
- Buffalo County 179
- Bennett County 413
- Butte County 678
Cite this page
“Brown County, South Dakota.” Severe Weather History. severeweatherhistory.com/county/south-dakota/brown-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.