116
Recorded events
1
Direct deaths
0
Direct injuries
$8.8M
Property damage
Flood in Sioux County, Iowa: 116 recorded events between 2006 and 2025. The strongest on record measured 0. That places the county #41 nationally and #5 statewide for this hazard.
Decade by decade
Flood in Sioux County, Iowa: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flood in Sioux County is the 2010s, when 89 of the county's 116 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 Sioux County archive, flood makes up 16.8% of all recorded severe weather across 8 hazard types. Nationally the county sits at #41 for this hazard and #5 within Iowa, putting it in the 98.7 percentile of all U.S. counties.
Seasonality
Events by month
Jun is the peak month for flood in Sioux County with 29 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.
Significant events
Deadliest on record
| Date | Location | Scale | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jun 20, 2024 | CHATSWORTH | 0 | 1 | 0 | $6.5M |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 31, 2025 | NEWKIRK | 0 | $0 |
| Jun 3, 2025 | ROCK VLY | 0 | $0 |
| Jul 1, 2024 | LEBANON | 0 | $0 |
| Jun 22, 2024 | MAURICE | 0 | $0 |
| Jun 22, 2024 | NEWKIRK | 0 | $0 |
| Jun 21, 2024 | ROCK VLY | 0 | $0 |
| Jun 21, 2024 | ROCK VLY | 0 | $0 |
| Jun 21, 2024 | SHELDON | 0 | $0 |
| Jun 21, 2024 | SHELDON | 0 | $0 |
| Jun 21, 2024 | FAIRVIEW | 0 | $0 |
Other hazards here
More from Sioux County
- Hail 256
- Thunderstorm Wind 223
- Tornado 47
- Flash Flood 41
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Repeated heavy rains caused record flooding of the Rock River. Several homes, businesses, roads, farmland, and other low areas were flooded, forcing some people to evacuate their homes and rely on Red Cross and other volunteer assistance for several days. The flooding was severe in Rock Valley, where the river crested at a record 6.68 feet above flood stage on June 17th, and where a levee break added to flooding in the town.
Repeated heavy rains caused record flooding of the Big Sioux River. Farmland and other lowlands including numerous roads were flooded, especially along the river in southwestern Sioux County, near and south of where the flooding Rock River empties into the Big Sioux. Some roads were damaged, and some secondary roads were washed out. Several homes and farm buildings were flooded and damaged. The river crested at a record 12.92 feet above flood stage at Hawarden on June 17th.
Persistent moderate to heavy rain caused flooding of fields and other lowlands, including several roads, homes, and businesses. This flooding lasted for almost two days, and was aggravated locally by additional storms during that time. Some roads were damaged or washed out.
Quick answers
Frequently asked
How many flood events are on record in Sioux County, Iowa?
116 flood events are recorded in Sioux County between 2006 and 2025, causing 1 direct deaths.
What is the strongest flood recorded in Sioux County?
The strongest flood on record in Sioux County measured 0.
Where does the flood data for Sioux 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 Sioux County, Iowa.” Severe Weather History. severeweatherhistory.com/county/iowa/sioux-county/flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.