45
Recorded events
0
Direct deaths
0
Direct injuries
$1.0M
Property damage
Flood in Hamlin County, South Dakota: 45 recorded events between 2007 and 2025. The strongest on record measured 0. That places the county #279 nationally and #18 statewide for this hazard.
Decade by decade
Flood in Hamlin County, South Dakota: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flood in Hamlin County is the 2010s, when 26 of the county's 45 recorded events were logged. Comparing decades is useful for spotting active periods, but the earliest years are thin because systematic reporting for this hazard began later.
Within the Hamlin County archive, flood makes up 12.0% of all recorded severe weather across 6 hazard types. Nationally the county sits at #279 for this hazard and #18 within South Dakota, putting it in the 90.3 percentile of all U.S. counties.
Seasonality
Events by month
Mar is the peak month for flood in Hamlin County with 12 recorded events, while Jan is the quietest. Seasonality here is a property of the archive as much as the climate: reports cluster where population and spotter networks are densest.
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Aug 22, 2025 | CASTLEWOOD | 0 | $0 |
| Aug 17, 2025 | STONE BRIDGE | 0 | $0 |
| Aug 17, 2025 | STONE BRIDGE | 0 | $0 |
| Aug 6, 2025 | CASTLEWOOD | 0 | $0 |
| Aug 1, 2025 | APPLEBY | 0 | $0 |
| Jul 28, 2025 | CASTLEWOOD | 0 | $0 |
| Jun 24, 2024 | APPLEBY | 0 | $0 |
| Jun 3, 2024 | CASTLEWOOD | 0 | $0 |
| May 23, 2024 | DEMPSTER | 0 | $0 |
| May 8, 2024 | THOMAS | 0 | $0 |
Other hazards here
More from Hamlin County
- Hail 192
- Thunderstorm Wind 93
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Snowmelt flooding damaged many roads and highways, including U.S. Highway 81, throughout Hamlin County. Many roads were closed throughout the county. In the late evening of April 13th on U.S Highway 81, a car with four people inside went through a flooded area at a high rate of speed and ended up in the flooded ditch. They all got out with no injuries.
The Big Sioux River went above and back below flood stage at the end of March. The river rose above flood stage of 11 feet to 12.87 feet at the gaging site at Castlewood. Minor flooding of agricultural land along with a few roads occurred.
The Big Sioux River near Castlewood entered flood stage around mid-day on August 6th. The river would crest at 1030 pm on August 7th at 10.63 feet, or 1.63 feet above flood stage. The river stayed in flood through the morning of August 10th. Flooding was mainly confined to low-lying agricultural lands north of Castlewood, though a portion of 184th street flooded.
Quick answers
Frequently asked
How many flood events are on record in Hamlin County, South Dakota?
45 flood events are recorded in Hamlin County between 2007 and 2025, causing 0 direct deaths.
What is the strongest flood recorded in Hamlin County?
The strongest flood on record in Hamlin County measured 0.
Where does the flood data for Hamlin County come from?
All events come from the NOAA/NCEI Storm Events Database, the federal public-domain archive of severe weather reports. Dates are UTC, damage is as reported and not inflation-adjusted, and the most recent entries may still be revised.
Cite this page
“Flood in Hamlin County, South Dakota.” Severe Weather History. severeweatherhistory.com/county/south-dakota/hamlin-county/flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.