Sioux County, Iowa severe weather history spans 690 recorded events between 1956 and 2025. The dominant hazard is hail, accounting for 37.1% of all recorded events. It ranks #416 nationally and #14 in Iowa.
690
Recorded events
2
Direct deaths
4
Direct injuries
$26.2M
Property damage
The record
What the Sioux County, Iowa severe weather history record shows
Across the archive, Sioux County, Iowa severe weather history averages 10.0 recorded events a year. The busiest stretch on record is the 2010s, with 234 events logged in that decade alone. Roughly 73 events fall before 1990 and 617 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Sioux County, Iowa record is thunderstorm wind, responsible for 1 direct deaths. The costliest is tornado, with $12.6M 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 Sioux County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 256 | 0 | $320K | 2.75 | 1961–2025 |
| Thunderstorm Wind | 223 | 1 | $2.8M | 87 | 1956–2025 |
| Flood | 116 | 1 | $8.8M | 0 | 2006–2025 |
| Tornado | 47 | 0 | $12.6M | F3 | 1963–2024 |
| Flash Flood | 41 | 0 | $1.7M | 0 | 1999–2025 |
| Heavy Rain | 3 | 0 | $0 | 0 | 2014–2016 |
| Lightning | 2 | 0 | $40K | 0 | 1998–2009 |
| Funnel Cloud | 2 | 0 | $0 | 0 | 2009–2015 |
Decade by decade
Sioux County, Iowa severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
61 mapped tornado paths intersect this county: 55 touched down inside it and 6 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1971-05-31 | EF3 | 0 | 0 | 46.5 mi | Touched down here |
| 1968-09-22 | EF3 | 0 | 0 | 4.7 mi | Touched down here |
| 2008-05-01 | EF2 | 0 | 0 | 13.0 mi | Touched down here |
| 1987-07-07 | EF2 | 0 | 0 | 8.0 mi | Crossed in |
| 1981-06-13 | EF2 | 0 | 0 | 0.1 mi | Touched down here |
| 1979-08-08 | EF2 | 0 | 0 | 0.4 mi | Touched down here |
| 1978-07-05 | EF2 | 0 | 0 | 11.9 mi | Touched down here |
| 1966-06-02 | EF2 | 0 | 0 | 11.5 mi | Touched down here |
| 1954-06-19 | EF2 | 0 | 0 | 2.3 mi | Crossed in |
| 2024-04-16 | EF1 | 0 | 0 | 1.0 mi | Touched down here |
Significant events
Deadliest events on record in Sioux County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jun 20, 2024 | Flood | CHATSWORTH | 1 | 0 | $6.5M |
| Jul 25, 2005 | Thunderstorm Wind | SHELDON | 1 | 0 | $50K |
| Jul 22, 2010 | Thunderstorm Wind | MAURICE | 0 | 4 | $200K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Thunderstorm winds flipped over a camper, twisted swing sets, blew down power poles, and caused widespread tree damage. Several trees were blown down, including one which fell on a tent, killing a participant in a bicycle ride across Iowa. Several roads were blocked by fallen trees and limbs. Wind blown debris damaged siding on several houses.
Water ponding in the area of Central Park overflowed roadways and entered the Sioux Center Fire Department building. Two homes suffered the collapse of basement walls from the high water. Water also inundated a transformer which cut off power to seven homes in the northwest part of town. Seven trailers were evacuated due to high water in Westbrook Village on the northwest edge of town. More than two dozen vehicles were stranded in high water. Damage costs are rough estimates.
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.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
36,212
Population (ACS)
$250K
Median home value
15
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Jun 24, 2024 | Severe Storm | SEVERE STORMS, FLOODING, STRAIGHT-LINE WINDS, AND TORNADOES | DR |
| Mar 23, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Mar 23, 2019 | Flood | SEVERE STORMS AND FLOODING | DR |
| Aug 20, 2018 | Severe Storm | SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODING | DR |
| Jul 24, 2014 | Flood | SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODING | DR |
Within the county
Most affected places
- Rock Vly 152
- Fairview 142
- Lebanon 136
- Hawarden 132
Quick answers
Frequently asked
How many severe weather events have been recorded in Sioux County, Iowa?
690 events are on record between 1956 and 2025, causing 2 direct deaths and $26.2M in property damage.
What is the most common severe weather hazard in Sioux County?
Hail, with 256 recorded events — 37.1% of everything in the archive for this county.
How many tornadoes have crossed Sioux County?
61 mapped tornado paths intersect the county boundary; 55 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Sioux County?
15 federal disaster declarations from FEMA include Sioux County, each tied to a specific incident period.
How risky is Sioux County compared with the rest of the country?
FEMA's National Risk Index rates Sioux County as relatively low risk, placing it in the 52 percentile of its state for expected annual loss.
Where does the Sioux County, Iowa 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
- Shelby County 303
- Story County 1,100
- Scott County 1,008
- Tama County 431
- Sac County 292
- Taylor County 442
Cite this page
“Sioux County, Iowa.” Severe Weather History. severeweatherhistory.com/county/iowa/sioux-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.