Tornadoes · United States · Iowa

Tornadoes in Sioux County, Iowa

50 tornadoes have crossed Sioux County since 1950, 16th of the 99 counties in Iowa with a tornado on record, an average of one every 1.5 years. They have killed 0 people and injured 1. None was rated F4 or above.

The rating scale

Tracks are drawn in the color of the rating. The United States rated tornadoes on Ted Fujita’s F scale until 31 January 2007 and on the Enhanced Fujita scale after it. Both run from 0 to 5, and both rate the damage rather than measure the wind: the speeds are what that damage is taken to imply.

  1. F0 / EF040 to 72 mph on the F scale, 65 to 85 mph on the EF scale

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F1 / EF173 to 112 mph on the F scale, 86 to 110 mph on the EF scale

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2 / EF2113 to 157 mph on the F scale, 111 to 135 mph on the EF scale

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3 / EF3158 to 206 mph on the F scale, 136 to 165 mph on the EF scale

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4 / EF4207 to 260 mph on the F scale, 166 to 200 mph on the EF scale

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5 / EF5261 to 318 mph on the F scale, over 200 mph on the EF scale

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Now

Tornadoes
50
Deaths
0
Injuries
1
F4 and above
0
Worst on record
F3, July 5, 1978

The strongest

  1. F3, Sioux County, IowaJuly 5, 1978F3, 8.0 mi (13 km)
  2. F3, Sioux County, IowaSeptember 22, 1968F3, 4.7 mi (8 km)
  3. EF2, Sioux and Lyon counties, IowaMay 1, 2008EF2, 12.9 mi (21 km)
  4. F2, Sioux County, IowaJuly 5, 1978F2, 11.9 mi (19 km)
  5. F2, Sioux County, IowaJune 2, 1966F2, 11.5 mi (19 km)
  6. F2, Union and Sioux counties, South Dakota and IowaJuly 7, 1987F2, 8.0 mi (13 km)
  7. F2, Sioux County, IowaAugust 8, 1979F2, 0.4 mi (1 km)
  8. F2, Sioux County, IowaJune 13, 1981F2, 0.1 mi (0 km)

Every year with a tornado

The 28 years of the 76 in the record with a tornado in Sioux County. Each year links to every tornado in Iowa that year.

YearTornadoesDeathsInjuriesStrongest
20244EF0
20232EF0
20172EF0
20161EF0
20154EF0
20142EF1
20122EF0
20111EF0
20101EF0
20082EF2
20071EF0
20053F1
20041F0
20013F1
20001F1
19983F0
19932F1
19922F1
19901F0
19871F2
19811F2
19791F2
19782F3
19751F1
19683F3
19661F2
19631F1
195811F1

Every tornado that crossed Sioux County

50 tornadoes, newest first. 1 of them touched down in a neighboring state and ran in, so the record files it under that state rather than Iowa.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 31, 20244:36 PM CDTEF0Sioux0.725
April 16, 20242:30 PM CDTEF0Sioux0.325
April 16, 20242:27 PM CDTEF0Sioux0.925
April 16, 20242:11 PM CDTUnratedSioux0.010
August 5, 20232:42 PM CDTUnratedSioux0.110
August 5, 20232:30 PM CDTEF0Sioux0.930
May 17, 20172:42 PM CDTEF0Sioux0.010
May 17, 20172:10 PM CDTEF0Sioux0.010
May 23, 20164:41 PM CDTEF0Sioux0.125
October 23, 20156:01 PM CDTEF0Sioux0.250
October 23, 20155:49 PM CDTEF0Sioux0.150
October 23, 20155:38 PM CDTEF0Sioux0.250
May 10, 20153:28 PM CDTEF0Sioux0.850
May 11, 20148:50 PM CDTEF0Sioux0.950
May 11, 20148:35 PM CDTEF1Sioux3.9100$3.0 million
May 4, 20123:22 PM CDTEF0Sioux0.550
May 4, 20123:15 PM CDTEF0Sioux0.550
May 11, 20116:53 PM CDTEF0Sioux0.550
June 25, 201010:53 PM CDTEF0Sioux0.250
May 1, 20086:59 PM CDTEF2Sioux12.9400$510,000
May 1, 20086:55 PM CDTEF0Sioux0.150
September 30, 20074:27 PM CDTEF0Sioux0.150
November 12, 20054:30 PM CSTF1Sioux1.0100$800,000
June 4, 200510:22 PM CDTF0Sioux0.150
June 4, 200510:02 PM CDTF0Sioux0.150
April 18, 20045:15 PM CDTF0Sioux0.150
August 17, 20015:35 PM CDTF1Sioux1.0100$50,000
August 17, 20015:29 PM CDTF1Sioux3.0100$100,000
June 12, 20016:45 PM CDTF0Sioux0.150
July 9, 20009:15 PM CDTF1Lyon3.0100$60,000
May 15, 19984:20 PM CDTF0Sioux0.150
May 15, 19984:13 PM CDTF0Sioux0.150
May 15, 199811:30 AM CDTF0Sioux1.050$30,000
June 7, 19936:42 PM CDTF0Sioux0.320$500 to $5,000
June 7, 19936:38 PM CDTF1Sioux7.530$50,000 to $500,000
July 9, 19926:35 PM CDTF1Sioux1.023$5,000 to $50,000
June 16, 19929:55 PM CDTF0Sioux0.213$50 to $500
June 19, 19904:30 AM CDTF0Sioux0.220$50,000 to $500,000
July 7, 19871:10 AM CDTF2Union to IA8.050
June 13, 19819:30 PM CDTF2Sioux0.110$500 to $5,000
August 8, 197910:30 AM CDTF2Sioux0.4100$500,000 to $5 million
July 5, 19787:00 PM CDTF2Sioux11.9200$500,000 to $5 million
July 5, 19786:30 PM CDTF3Sioux8.0100$5,000 to $50,000
June 3, 197512:00 AM CDTF1Sioux0.110$500 to $5,000
September 22, 19685:35 PM GMT-5F0Sioux0.110
September 22, 19685:30 PM GMT-5F0Sioux0.110
September 22, 19685:00 PM GMT-5F3Sioux4.750$500,000 to $5 million
June 2, 19669:25 PM GMT-5F2Sioux11.5300$5,000 to $50,000
March 16, 19631:00 PM GMT-6F1Sioux4.7300$5,000 to $50,000
April 5, 195810:00 AM GMT-6F1Woodbury37.01001$5,000 to $50,000

Nearby

Warnings in force in Sioux CountyThe forecast for Sioux CountyThe live radar over Sioux CountyEvery county in Iowa

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.